JP2005059776A - Carrier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively actuate braking force with respect to a carrier. <P>SOLUTION: Both drive wheels 14 are equipped with a wheel brake 41 operated from a steering wheel 20 side through cables 49 and 50. When the wheel brake 41 actuates and a detection switch 57 detects it at the time of electric traveling, a current carrying switch 25 in a drive circuit 22 of a motor M is turned off, supply of the electric current to the motor M is shut off, and PWM control is performed on a braking switch 28 side arranged on a short circuit line 26. At this place, brake control by electromagnetic induction is carried out while varying a duty ratio so that an actual speed from an encoder 59 is made to be a target speed "0". That is, braking by electromagnetic induction can be actuated in addition that a hand brake 40 can be actuated without difficulty even in electrical traveling. Thus, the braking force can be effectively actuated with respect to the carrier. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a transport vehicle having an auxiliary electric function.

Some of the distribution vehicles used in hospitals or the like have an auxiliary electric function. This auxiliary electric function is equipped with a motor and is connected to the drive wheel. When the handle is pulled or pushed manually by a hand, the motor, that is, the drive wheel is rotated at a rotation speed corresponding to the rotation amount of the handle. By driving and self-running, the running operation is assisted. Note that this type of auxiliary electric function is described in Patent Document 1, for example.
JP 2001-106082 A

By the way, when stopping a power train that has been electrically driven conventionally, the steering wheel is gradually decelerated and stopped by returning the handle to the neutral position. In general, the brake by induction is functioning and is stopped relatively slowly. This is due to the situation peculiar to the allocation car, such as feeding lunches on a tray.
However, even with such a layout vehicle, it is necessary to apply a large amount of braking when it is unavoidable to stop suddenly or travel downhill, and improvements for that purpose have been anxious.
The present invention has been completed based on the above circumstances, and an object of the present invention is to efficiently apply a braking force to a transport vehicle.

  As a means for achieving the above object, the invention according to claim 1 is directed to an operation from the handle side in a transport vehicle capable of assisting travel by driving a drive wheel with a motor when traveling with a handle. The mechanical braking means for applying braking to the wheels in the above, the electromagnetic braking means for applying braking to the motor by electromagnetic induction, the detecting means for detecting that the mechanical braking means is operated, and the detecting means And a braking control means for operating the electromagnetic braking means based on the detection signal.

According to a second aspect of the present invention, in the vehicle according to the first aspect, the braking control means receives the detection signal from the detection means when the transport vehicle is electrically driven, thereby receiving the detection signal from the power supply. It is characterized in that it functions to operate the electromagnetic braking means after being shut off.
According to a third aspect of the present invention, in the electromagnetic brake according to the first or second aspect, the electromagnetic braking means alternately repeats opening and closing of a braking switch for short-circuiting both ends of the motor winding in the motor in a predetermined cycle. And having a function of changing the ratio of the closing time.

<Invention of Claim 1>
When the mechanical braking means is actuated, this is detected and the electromagnetic braking means acts together, and braking can be efficiently applied to the transport vehicle. Therefore, it is possible to appropriately cope with a case where the transport vehicle is unavoidably stopped suddenly or smoothly travels downhill.

<Invention of Claim 2>
In the case of electric traveling, when the operation of the mechanical braking means is detected, the motor is disconnected from the power source so that the mechanical braking means can be operated without any trouble, and the electromagnetic braking means is Operate together. Even when the vehicle is electrically driven, the mechanical braking means can be used, and at the same time, the electromagnetic braking means can be operated to efficiently apply the braking.
<Invention of Claim 3>
When the brake switch is closed, a braking force by electromagnetic induction acts, and the magnitude of the braking force can be controlled by changing the ratio of the closing time.

Hereinafter, an embodiment in which the present invention is applied to a trolley will be described with reference to the drawings.
<Embodiment 1>
A first embodiment of the present invention will be described with reference to FIGS.
In FIG. 1, reference numeral 10 denotes a main body of the hot and cold distribution wheel, and two pairs of a hot storage room 11 </ b> A and a cold storage room 12 </ b> A and a hot storage room 11 </ b> B and a cold storage room 12 </ b> B are provided side by side. Yes. In the following description, the right side of FIG.
As shown in FIG. 3, a pair of left and right wheels 13, 14 are mounted on the bottom surface of the main body 10, the front end side is the free wheel 13, and the rear end side is supported by the drive shaft 15. The driving wheel 14 is provided. As will be described in detail later, a reversible motor M capable of driving the drive wheels 14 in both forward and reverse directions is provided above the drive shaft 15 and connected to the drive shaft 15 via a mission unit 16.

A control box 18 is provided on the front surface of the main body 10 and accommodates a control mechanism for controlling the driving of the motor M. A handle 20 having a gate shape is supported on the control box 18 so as to be rotatable about an axis 20A, and is always urged so as to take a neutral posture standing upright.
The arrangement vehicle is advanced by the operator turning the handle 20 forward (arrow A direction in FIG. 1) and pulling, and the handle 20 is rotated backward (arrow B direction in FIG. 1). It is designed to be retracted by pressing.

  As shown in FIG. 6, the motor M is driven and controlled by a signal from the control unit 21, and the drive circuit 22 of the motor M is schematically shown in FIG. The motor M is connected to a DC power supply 24 by a power supply line 23, and an energization switch 25 is interposed in the power supply line 23. The motor M is connected to a short-circuit wire 26 so as to short-circuit both ends of the motor winding, and a diode 27 is interposed in the middle. A brake switch 28 is interposed in the short-circuit wire 26. Yes.

On the other hand, as shown in FIG. 6, the handle 20 is equipped with a variable resistor 30. When the handle 20 is in the neutral position, the slider 31 is located at the center of the resistance element 32. When the handle 20 is rotated forward, the slider 31 moves in a direction in which the resistance value increases, that is, the output voltage increases. Is rotated rearward, the slider 31 moves in a direction in which the resistance value decreases, that is, the output voltage decreases.
Further, a micro switch 33 is provided for detecting when the handle 20 is rotated either forward or backward from the neutral position, and the output voltage when the rotation is detected is larger or smaller than a reference value. Whether the handle 20 is rotated forward or backward is identified.

The drive control of the motor M during auxiliary electric travel will be described below with reference to FIGS. When the auxiliary electric travel is selected by the changeover switch 35 provided on the operation panel, the brake switch 28 of the short-circuit line 26 is kept closed.
Here, when the handle 20 is rotated forward from the neutral position, the motor M is energized in the forward direction. On the other hand, when the handle 20 is rotated backward, the motor M is reversed. And the rotational speed of the motor M is controlled in accordance with the amount of rotation of the handle 20. Specifically, the higher the amount of rotation of the handle 20, the higher the speed is controlled.

A PWM (Pulse Width Modulation) method is employed for controlling the rotational speed of the motor M described above. As shown in FIG. 8, the energizing switch 25 is repeatedly turned on and off at a constant period c. When the energizing switch 25 is turned on, the motor M is energized and driven, while the energizing switch 25 is turned on. When turned off, only the closed circuit for braking by the short-circuit line 26 is configured and acts so that braking is applied by electromagnetic induction.
Then, the ON section x of a pulse having a constant period c (for example, 66 μs) is made variable, that is, the duty ratio is changed so that the average voltage is changed to energize the motor M. The higher the duty ratio, the higher the speed control. The

  Now, in this embodiment, the handbrake 40 is equipped. The operating part is an inwardly expanding wheel brake 41, which is mounted on both drive wheels 14. Specifically, as shown in FIG. 5, the wheel brake 41 has a pair of pads 43 arranged inside a brake cover 42 that rotates integrally with the drive wheel 14, and is always separated from the brake cover 42 by a biasing spring 44. When the brake arm 45 is rotated in the direction of the arrow C in the figure, the pair of pads 43 are moved to the arrow by the cam action accompanying the rotation of the cam body 46 as indicated by the chain line in the figure. As indicated by line D, the drive wheel 14 is braked by being elastically pressed against the inner periphery of the brake cover 42 against the spring force of the biasing spring 44.

The wheel brake 41 is operated from the handle 20 side via a cable. Therefore, as shown in FIG. 2, a brake lever 48 is provided at the grip portion 20 </ b> B of the handle 20.
The cable includes a single operation side cable 49 and a pair of drive side cables 50. These cables 49, 50 are slidably inserted through a wire 52 in a flexible tube 51. Structure. On the other hand, as shown in FIG. 3, a connection mechanism 54 for cables 49 and 50 is provided at a substantially central portion on the bottom surface of the main body 10.

A wire on one end side of the operation side cable 49 is connected to the brake lever 48, and the other end side is routed with the front side of the main body 10 facing downward as shown in FIG. The other end of the tube 51 is fixed to the front plate 54 </ b> A of the connection mechanism 54, and the other end of the wire 52 is fixed to the central portion of the connection plate 55.
As for both the drive side cables 50, the wire 52 of the one end side is fixed to the brake arm 45 of each wheel brake 41 mentioned above, the other end of both the tubes 51 is fixed to the rear board 54B of the connection mechanism 54, and both wires 52 The other end is fixed to both ends of the connecting plate 55 described above.
Therefore, when the brake lever 48 is gripped, the wire 52 of the operation side cable 49 is pulled, and the wires 52 of both the drive side cables 50 are also pulled in the direction of arrow E in FIGS. As a result, the brake arms 45 of the wheel brakes 41 are rotated in the direction of the arrow C in FIG. 5 so that mechanical braking is applied to the drive wheels 14 as described above.

Detection switches 57 are provided in the vicinity of the brake arms 45 of both wheel brakes 41, and are provided integrally with the brake arm 45 as shown by the solid line in FIG. 4 when the wire 52 is not pulled. When the actuated member 56 presses the actuator 58 and the detection switch 57 is turned on, the wire 52 is pulled and the brake arm 45 and the actuating member 56 are rotated as shown by the chain line in FIG. The pressure switch 58 is removed and the detection switch 57 is turned off.
As shown in FIG. 6, the two detection switches 57 are connected in series to the control unit 21 and are turned on when the detection switch 57 is cut off in terms of the circuit. When both are cut off (when turned on in terms of circuit), the detection circuit 58 is energized. As a result, the energization switch 25 of the motor drive circuit 22 is controlled to be turned off.

As will be described in detail later, the control unit 21 can apply PWM electromagnetic braking when the energization switch 25 is turned off. As shown in FIG. 8, the brake switch 28 in the drive circuit 22 is repeatedly turned on and off at a constant cycle c (66 μs), and the on section y is variably controlled.
The control unit 21 is connected to an encoder 59 that detects the number of rotations of the motor M, and the detected value detected by the encoder 59 is controlled together with the output voltage from the variable resistor 30 to control electromagnetic braking. Is being used for.

Subsequently, various aspects in the case of stopping the arrangement vehicle will be described. First, for comparison, a case where the hand is simply released from the handle 20 without using the hand brake 40 will be described.
When the vehicle is electrically driven, as shown in the flowchart of FIG. 9, when the hand is released from the handle 20 (“YES” in step S1), the handle 20 gradually returns toward the neutral position until it returns to the neutral position. (Step S2 is “NO”), the energization switch 25 of the drive circuit 22 is PWM-controlled (Step S3). That is, every 25 ms, the actual speed V0 obtained from the encoder 59 and the target speed V obtained from the variable resistor 30 are seen to determine the duty ratio so that the actual speed V0 is directed to the target speed V. At this time, since the target speed V is smaller, the duty ratio is smaller, and conversely, braking by electromagnetic induction associated with the construction of only the closed circuit of the short-circuit line 26 when the energization switch 25 is turned off is effective. And gradually decelerate. The speed of the arrangement vehicle during this time is indicated by a region X1 in the characteristic line X of the graph of FIG.

When the handle 20 returns to the neutral position (“YES” in step S2), the energization switch 25 is turned off as the micro switch 33 is turned off, and PWM control on the brake switch 28 side is performed (step S4). . Here again, every 25 ms, the duty ratio is changed so that the actual speed V0 from the encoder 59 is directed to the target speed V from the variable resistor 30, and braking control by electromagnetic induction is performed. At this time, since the handle 20 has already returned to the neutral position, the target speed V becomes “0”. In short, PWM braking control with the target speed V set to “0” is performed. The speed of the arrangement vehicle at this time is shown in a region X2 of the characteristic line X.
After that, when it is detected that the actual speed from the encoder 59 is V0 “0” and the layout vehicle has stopped (step S5), the electromagnetic brake is activated (step S6).

When manual switching is selected by the changeover switch 35, the energization switch 25 is in an off state, and the PWM braking control related to the braking switch 28 is always performed (from step S1 to step S4). Will be in a transitional state). However, for a while after being released, PWM braking control is performed according to the difference between the actual speed V0 from the encoder 59 and the target speed V from the variable resistor 30. When the handle 20 returns to the neutral position, PWM braking control is performed in accordance with the difference between the actual speed V0 and the target speed V "0".
Thereafter, similarly to the above, the arrangement vehicle stops and the electromagnetic brake is applied (steps S5 and S6).

Next, a case where the hand brake 40 is applied will be described.
When the vehicle is electrically driven, as shown in the flowchart of FIG. 10, when the brake lever 48 is gripped (step S11 is “YES”), the wheel brake 41 is applied and mechanical braking is applied (step S12). . At the same time, both detection switches 57 are turned on (step S13). Thereby, regardless of the position of the handle 20, the energization switch 25 of the drive circuit 22 of the motor M is turned off.
As a result, the power supply to the motor M is cut off, and at the same time, the PWM control on the brake switch 28 side is performed. That is, every 25 ms, braking control by electromagnetic induction is performed while changing the duty ratio so that the actual speed V0 from the encoder 59 is directed to the target speed V, but both detection switches 57 are turned on as described above. At this time, regardless of the position of the handle 20, that is, the output value of the variable resistor 30, PWM control is performed with the target speed V always set to “0” (step S14).

As shown by the characteristic line Y in the graph of FIG. 11, the deceleration curve of the layout vehicle based on the PWM braking control is slightly gentler than that in the case where the handle 20 is released. Since a mechanical braking force is applied by the wheel brake 41, the distribution vehicle is stopped in a short time as shown by the characteristic line Z in FIG.
Thereafter, similarly, when it is detected that the distribution vehicle has stopped (step S15), the electromagnetic brake is activated (step S16).

In the case of manual travel, the energization switch 25 is in an off state and the PWM braking control related to the braking switch 28 is always performed. However, as both detection switches 57 are turned on, the electric switch As in the case of traveling, PWM control is performed in which the target speed V is always “0” regardless of the position of the handle 20, that is, the output value of the variable resistor 30.
After that, similarly, the arrangement vehicle stops and the electromagnetic brake acts.

As described above, according to the present embodiment, when the hand brake 40 is used during the electric running, the PWM control is performed after the power to the motor M is cut off. In other words, in addition to being able to act on mechanical braking without hindrance even during electric travel, it is also possible to act on braking by electromagnetic induction. When stopping or running smoothly on a downhill, it is possible to respond effectively.
Further, even during manual travel, in addition to the hand brake 40, a braking force by electromagnetic induction can be obtained together, so that a large braking force can be obtained.

<Embodiment 2>
Next, a second embodiment of the present invention will be described with reference to FIGS. In the second embodiment, the main operation unit 60M and the sub operation unit 60S are provided on both front and rear sides of the vehicle (see FIG. 1), and the handle 20 is provided in each of the main operation unit 60M and the sub operation unit 60S. In the arrangement vehicle that can perform auxiliary electric traveling by switching, the hand brake 40 can be operated from both the main and sub operation portions 60M and 60S.

The front main operation portion 60M side is the same as that of the first embodiment, and the other end of the operation side cable 49M connected to the brake lever 48 provided on the grip portion 20B of the handle 20 is connected to the bottom surface of the main body 10. Led.
On the other hand, as shown in FIG. 13, the grip lever 20B of the handle 20 provided on the sub operation section 60S side is similarly provided with a brake lever 48, and the other operation side cable 49S is connected to the brake lever 48. The wire on one end side is connected, and the other end side is routed with the rear surface side of the main body 10 facing downward as shown in FIG.

  A coupling mechanism 62 is provided at the substantially central portion of the bottom surface of the main body 10. A pair of left and right levers 63M and 63S are supported by the coupling mechanism 62 so as to be rotatable about a shaft 64. The levers 63M and 63S are stepped up and down, and are arranged at the end of the abutting side. Each has a long hole 65 and is wrapped up and down. On the other hand, a connecting plate 66 is provided at a position between both levers 63M and 63S, and a pin 67 provided through the connecting plate 66 is fitted in the elongated hole 65 of both levers 63M and 63S.

The other ends of the tubes 51 of the operation side cables 49M and 49S drawn from the main and sub operation portions 60M and 60S are fixed to both ends of the rear plate 62A of the coupling mechanism 62, and the other ends of the respective wires 52 are The levers 63M and 63S are connected to the end portions on the side away from each other.
Further, the other end of the tube 51 in the both drive side cables 50 drawn from the wheel brakes 41 provided on the left and right drive wheels 14 is fixed to the center portion of the rear plate 62A of the coupling mechanism 62, The end is fixed to the connecting plate 66 described above.

Therefore, when the brake lever 48 is gripped on the main operation portion 60M side, the wire 52 of the operation side cable 49M is pulled, and the connecting plate 66 is moved in the reverse direction while rotating the lever 63M as shown by the chain line in FIG. By pulling, the wires 52 of both the drive side cables 50 are pulled, and the wheel brake 41 acts. Further, when the brake lever 48 is gripped on the side of the sub operation portion 60S, as shown in FIG. 16, the wire 52 of the operation side cable 49S is pulled, and the connecting plate 66 is moved in the reverse direction while rotating the lever 63S on the opposite side. Similarly, the wire 52 of both the drive side cables 50 is pulled, and the wheel brake 41 acts.
That is, the hand brake 40 can be applied in the same manner from either of the main / sub operation units 60M and 60S.

<Related technologies>
In this type of arrangement vehicle, it is convenient if various information such as driving conditions can be notified to the operator and surrounding people. Therefore, in this related technology, as shown with reference to FIG. 6, an audio device is provided in the control unit 21, so that various types of information can be output as audio and can be played from a speaker 70 equipped in a machine room or the like. It is like that. The presence or absence of output from the speaker 70 can be selected with the switch 71.
As voice guidance,
"You are driving. Please be careful."
“There was an obstacle and it stopped.”
"An error has occurred. The content of the error is ..."
“The battery is low. Please charge.”
“Charging started.”
“Charging is finished.”
Etc.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention, and further, within the scope not departing from the gist of the invention other than the following. Various modifications can be made.
(1) In the above embodiment, the PWM type is used to control braking by electromagnetic induction. However, for example, the control may be performed in an analog manner by changing the resistance value of a resistor provided in the short-circuit line. .
(2) The present invention can be widely applied not only to a trolley car but also to all transport vehicles having an auxiliary electric function.

Front view of the garage according to the first embodiment The right side view Bottom view Partial front view showing the structure near the drive wheels Front view showing the structure of the wheel brake Block diagram of braking control mechanism Circuit diagram of motor drive circuit Explanatory drawing of motor energization operation (short circuit operation) Flow chart showing normal stop operation Flow chart showing stop operation by handbrake Graph showing deceleration curve Bottom view of the arrangement vehicle of the second embodiment The left side view Sectional view showing the structure of the coupling mechanism The plan view Plan view of the coupling mechanism when the hand brake is applied from the sub-operation unit

Explanation of symbols

  DESCRIPTION OF SYMBOLS M ... Motor 10 ... Distribution vehicle body 14 ... Drive wheel 20 ... Handle 21 ... Control part (braking control means) 22 ... Drive circuit 23 ... Power supply line 24 ... Power supply 25 ... Current switch 26 ... Short-circuit wire (electromagnetic braking means) ... Brake switch (electromagnetic brake means) 30 ... Variable resistor 40 ... Hand brake 41 ... Foil brake 49, 50 ... Cable 57 ... Detection switch (detection means) 59 ... Encoder

Claims (3)

When traveling with a handle, in a transport vehicle that can assist driving by driving a drive wheel with a motor,
Mechanical braking means for applying braking to the wheel by operation from the handle side;
Electromagnetic braking means for applying braking to the motor by electromagnetic induction;
Detecting means for detecting that the mechanical braking means is activated;
A transport vehicle comprising braking control means for operating the electromagnetic braking means based on a detection signal of the detection means. The braking control means functions to operate the electromagnetic braking means after the motor is disconnected from the power source by receiving a detection signal of the detection means when the transport vehicle is electrically driven. The transport vehicle according to claim 1. The electromagnetic braking means is characterized in that a braking switch for short-circuiting both ends of a motor winding in the motor has a function of alternately repeating opening and closing in a predetermined cycle and changing a closing time ratio. Item 3. The vehicle according to item 1 or 2.

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