CN103048279B - Sine mechanism used for spectrophotometer - Google Patents

Abstract

The invention provides a sinusoidal mechanism for a spectrophotometer, comprising: a motor (10); a bracket (2); a screw rod (3) arranged on the bracket (2) and driven by the motor (10); arranged on the bracket (2), and the guide rod (6) parallel to the screw mandrel (3); the slider (4), the slider (4) has a first through hole and a sleeve member (11), in the first through hole There is an internal thread on the inner peripheral surface, and the slider (4) is assembled on the screw rod (3) in the state where the internal thread meshes with the external thread on the screw rod (3), and the socket member (11) is tightly socketed around it. It is on the guide rod (6) and enables the slider (4) to move only along the axial direction of the guide rod (6). Through the precise fit between the sleeve member (11) and the guide rod (6), the left and right or up and down movement of the slider (4) caused by the small gap between the screw rod (3) and the slider (4) is limited Shaking, which can improve the wavelength repeatability of the spectrophotometer.

Description

Sinusoidal mechanism for spectrophotometers

technical field

The invention relates to a sinusoidal mechanism for a spectrophotometer, in particular to a sinusoidal mechanism with a mechanical device for preventing slide blocks from shaking.

Background technique

As an instrument for analyzing and testing the environment, metal semiconductors, and petrochemical polymer materials, the atomic absorption spectrophotometer is widely used in the fields of medicine, biology, and pharmacy.

In existing spectrophotometer products, a sinusoidal mechanism is usually used to convert the linear motion of the slider into the rotation of the grating via a swing rod connected to a turntable on which the grating is placed. Fig. 1 and Fig. 2 are respectively the front sectional view and the left sectional view of a conventional sinusoidal mechanism for a spectrophotometer. As shown in Fig. 1 and Fig. 2, the specific structure of the existing sinusoidal mechanism for spectrophotometer is, comprising: motor 10; It is rotatably assembled on the bracket 2 and can be driven to rotate by the motor 10 ; a guide rod 6 with both ends fixedly mounted on the bracket 2 and arranged parallel to the screw rod 3 ; and a slider 4 . A first through hole along the left and right direction of FIG. 1 is provided at approximately the middle of the vertical direction of FIG. The internal thread and the external thread on the threaded mandrel 3 are engaged to assemble on the threaded mandrel 3 . The bottom of slide block 4 has the slit 13 that runs through slide block 4 in the left-right direction of Fig. 1 and communicates with the lower peripheral surface of the first through hole and the lower side end face of slide block 4. 1 is provided with a threaded hole passing through the slider 4 in the direction perpendicular to the paper surface, and a screw 5 is screwed in the threaded hole. By adjusting the tightness of the screw 5, the slit width of the slit 13 can be changed, and then the slit 13 can be adjusted. The gap between the internal thread of the first through hole and the external thread of the screw rod 3 ensures a high-precision thread fit. On the upper end surface of the slider 4, there is a groove 12 that runs through the left and right sides of the slider 4 (the left and right direction in Fig. 1), and the guide rod 6 is penetrated in the groove 12. The guide slider 4 moves left and right along the guide rod 6 . In the roughly central position of the left-right direction (left-right direction among Fig. 1) of described groove 12, be provided with a circular hole along the direction perpendicular to paper surface of Fig. 1, one end of it is conducted with groove 12, and the other end is closed, A spring 8 is installed in the round hole, one end of the spring 8 abuts against the closed end of the round hole, and the other end of the spring 8 is pressed on the guide rod 6 via the steel ball 9 . Through such a structure, the gap between the groove 12 of the slider 4 and the guide rod 6 along the direction perpendicular to the paper in FIG. 1 can be eliminated, so as to limit the movement of the slider 4 in the direction perpendicular to the paper in FIG. purpose of exercise.

In addition, one end of the swing rod not shown in the figure is always in contact with the side wall on either side of the slider 4 through the tension spring, and the other end of the swing rod is connected to the turntable (not shown) on which the grating is placed. When the slider 4 moves left and right under the drive of the motor, the pendulum swings accordingly and drives the turntable to rotate, thereby converting the linear motion of the slider 4 into the rotation of the grating.

Contents of the invention

The problem to be solved by the invention

In the sinusoidal mechanism used in the spectrophotometer, the slider and the screw are screwed together, which requires high repeatability (that is, after the motor rotates forward by an angle and then reversely rotates by the same angle, the slider is required to return to the original position. s position). However, in order to allow the slider to move left and right with the rotation of the screw rod, there needs to be a certain gap between the threads in the thread transmission axis, and such a gap will make the movement of the slider along the guide rod unstable. Although in the above-mentioned existing sinusoidal mechanism, the rotation of the slider around the axis of the screw shaft can be limited by the pressing of the steel ball and the spring, the slider may still be damaged due to the gap between the internal thread of the slider and the external thread of the screw rod. Shake left and right or up and down, causing errors and resulting in a decrease in repeatability.

The present invention is developed to solve the above-mentioned problems, and its purpose is to provide a sinusoidal mechanism for a spectrophotometer with a mechanical device for preventing the slider from shaking and can eliminate the left and right or up and down shaking of the slider.

means of solving problems

In order to achieve the above object, the sinusoidal mechanism for the spectrophotometer involved in the present invention includes: a motor; a bracket; a screw rod that is arranged on the bracket and driven by the motor; A guide rod parallel to the screw rod; a slider, the slider has a first through hole and a sleeve member, and an internal thread is provided on the inner peripheral surface of the first through hole, and the slider uses the internal thread It is assembled on the screw rod in the state of meshing with the external thread on the screw rod, and the sleeve member is sleeved on the guide rod in a closed manner so that the slider can only move along the guide rod. Axial movement of the rod.

According to the sinusoidal mechanism for a spectrophotometer of the present invention, there are provided in the socket member along the circumferential direction perpendicular to the axial direction of the guide rod, which are equally distributed and parallel to the outer peripheral surface of the guide rod. There are at least three rows of balls arranged in the same direction, and the at least three rows of balls are pressed against the guide rod.

According to the sinusoidal mechanism for a spectrophotometer of the present invention, there are provided in the socket member along the circumferential direction perpendicular to the axial direction of the guide rod, which are equally distributed and parallel to the outer peripheral surface of the guide rod. The four rows of balls are arranged in the direction of the four rows of balls, and the four rows of balls are pressed against the guide rod.

According to the sinusoidal mechanism for a spectrophotometer of the present invention, the sleeve member is a linear bearing.

According to the sinusoidal mechanism for a spectrophotometer of the present invention, the socket member is a second through hole, and the cooperation between the second through hole and the guide rod makes the spectrophotometer scan the wavelength When the wavelength repeatability is ±0.1nm or less.

According to the sinusoidal mechanism for a spectrophotometer of the present invention, the socket member is a second through hole, and the cooperation between the second through hole and the guide rod makes the spectrophotometer scan the wavelength When the wavelength repeatability is ±0.05nm or less.

According to the sinusoidal mechanism for a spectrophotometer of the present invention, a bushing is also provided in the second through hole, and the cooperation between the bushing and the guide rod makes the spectrophotometer The wavelength repeatability during scanning is ±0.1nm or less.

According to the sinusoidal mechanism for a spectrophotometer of the present invention, a bushing is also provided in the second through hole, and the cooperation between the bushing and the guide rod makes the spectrophotometer The wavelength repeatability during scanning is ±0.05nm or less.

The effect of the invention

According to the present invention, since the sinusoidal mechanism is equipped with a mechanical device for preventing the slider from shaking, the left and right or up and down shaking of the slider can be eliminated, thereby improving the wavelength repeatability of the spectrophotometer during wavelength scanning. In addition, in the technical solution using linear bearings, since the balls roll with extremely small frictional resistance, the use load is small, and the slider can move smoothly with high precision.

Description of drawings

Fig. 1 is a front sectional view of a conventional sinusoidal mechanism for a spectrophotometer.

Fig. 2 is a left sectional view of a conventional sinusoidal mechanism for a spectrophotometer.

Fig. 3 is a front sectional view of an embodiment of a sinusoidal mechanism for a spectrophotometer according to the present invention.

Fig. 4 is a left sectional view of an embodiment of a sinusoidal mechanism for a spectrophotometer according to the present invention.

Symbol Description

1, 7...Bearing, 2...Bracket, 3...Screw rod, 4...Slider, 5...Screw, 6...Guide rod, 8...Spring, 9...Steel ball, 10...Motor, 11...Socket member, 12...Concave Groove, 13...slit

Detailed ways

Hereinafter, an embodiment of a sinusoidal mechanism for a spectrophotometer according to the present invention will be described with reference to FIGS. 3 and 4 . The same reference numerals as in FIGS. 1 and 2 are used in FIGS. 3 and 4 to designate the same or similar components.

3 and 4 show an embodiment of the present invention. Compared with the above-mentioned prior art, the main difference of this embodiment is that the socket member 11 is used instead of the groove 12 on the slider 4, and other structures are substantially the same as the prior art, and detailed descriptions are omitted here. As shown in Fig. 3 and Fig. 4, the sleeve member 11 is sleeved on the guide rod 6 in a closed manner so as to limit the movement of the slider 4 in all directions perpendicular to the axial direction of the guide rod 6, so that the slider 4 can only move along the axial direction of the guide rod 6.

In addition, as shown in Fig. 3 and Fig. 4, there are at least three rows arranged in the sleeve member 11 along the circumferential direction perpendicular to the axial direction of the guide rod 6 and arranged in a direction parallel to the outer peripheral surface of the guide rod. Balls, the at least three rows of balls are pressed against the guide rod 6. When the motor 10 drives the screw rod 3 to rotate so that the slider 4 moves left and right, the balls roll on the outer peripheral surface of the guide rod 6 with very small frictional resistance to guide the slider 4 . In this way, at least three rows of balls are equally distributed in the circumferential direction perpendicular to the axial direction of the guide rod 6, and are respectively in line contact with the guide rod 6, and press the guide rod in more than three directions perpendicular to the axial direction of the guide rod 6. The rod 6 can restrict the movement of the slider 4 in all directions perpendicular to the axial direction of the guide rod 6 , so that the slider 4 can only move along the axial direction of the guide rod 6 . Here, the so-called equal distribution refers to roughly equal distribution, and it is not required that the angles between two adjacent rows of balls relative to the axis of the guide rod 6 are strictly equal, as long as each row of balls is relatively evenly distributed on the guide rod 6. In the circumferential direction, it is sufficient to limit the movement of the slider 4 in all directions perpendicular to the axial direction of the guide rod 6 . In addition, in this embodiment, each row of balls is distributed in a straight line, but the present invention is not limited thereto, each row of balls can also be evenly distributed in other forms, for example, each row of balls can be parallel to each other in the sleeve member 11 spiral distribution.

In addition, as shown in Fig. 3 and Fig. 4, in this embodiment, there are provided in the sleeve member 11 which are equally distributed along the circumferential direction perpendicular to the axial direction of the guide rod 6 and along the outer circumference of the guide rod. There are four rows of balls arranged in a direction parallel to the surface, and the four rows of balls are pressed against the guide rod 6 .

In addition, as shown in FIG. 3 and FIG. 4 , the sleeve member 11 in this embodiment can be regarded as a bearing member with a bearing outer shell. In other embodiments of the present invention, the sleeve member 11 may also be a linear bearing having a bearing outer sleeve and a bearing inner sleeve structure.

In addition, in another embodiment of the present invention, the sleeve member 11 is a second through hole, and the second through hole is precisely matched with the guide rod 6, so that the sliding block 4 can be limited in the axial direction of the guide rod 6. The movement in all perpendicular directions makes the slider 4 only able to move along the axial direction of the guide rod 6 .

In addition, in yet another embodiment of the present invention, a bushing is also provided in the second through hole, and the bushing is closely matched with the guide rod 6 so as to limit the movement of the slider 4 against the guide rod 6 . The movement in all directions perpendicular to the axial direction of the slider 4 can only move along the axial direction of the guide rod 6 .

According to the present invention, since the sinusoidal mechanism is equipped with the sleeve member for preventing the slider from shaking, the left and right or up and down shaking of the slider can be eliminated, thereby effectively improving the wavelength repeatability of the spectrophotometer during wavelength scanning. According to the present invention, the wavelength repeatability of the spectrophotometer can be made ±0.1 nm or less, more preferably ±0.05 nm or less.

Claims (8)

1. A sinusoidal mechanism for a spectrophotometer, characterized in that it comprises: motor; bracket; set on the bracket and driven by the motor; a guide rod arranged on the bracket and parallel to the screw rod; A slider, the slider has a first through hole and a sleeve member, and an internal thread is provided on the inner peripheral surface of the first through hole, and the slider uses the internal thread and the thread on the screw rod The outer threads are engaged on the threaded rod, and the sleeve member is sleeved on the guide rod so that the sliding block can only move along the axial direction of the guide rod. 2. The sinusoidal mechanism according to claim 1, characterized in that, in the sleeve member, there are provided in the sleeve member along the circumferential direction perpendicular to the axial direction of the guide rod, which are equally divided and distributed along the outer peripheral surface of the guide rod. There are at least three rows of balls arranged in parallel directions, and the at least three rows of balls are pressed against the guide rod. 3. The sinusoidal mechanism according to claim 1, characterized in that, in the sleeve member, there are provided in the sleeve member along the circumferential direction perpendicular to the axial direction of the guide rod, which are equally divided and distributed along the outer peripheral surface of the guide rod. Four rows of balls arranged in a parallel direction, the four rows of balls press against the guide rod. 4. The sinusoidal mechanism according to any one of claims 1 to 3, wherein the sleeve member is a linear bearing. 5. The sinusoidal mechanism according to claim 1, wherein the socket member is a second through hole, and the cooperation between the second through hole and the guide rod makes the spectrophotometer at the wavelength The wavelength repeatability during scanning is ±0.1nm or less. 6. The sinusoidal mechanism according to claim 1, wherein the socket member is a second through hole, and the cooperation between the second through hole and the guide rod makes the spectrophotometer at the wavelength The wavelength repeatability during scanning is ±0.05nm or less. 7. The sinusoidal mechanism according to claim 5, wherein a bushing is also provided in the second through hole, and the cooperation between the bushing and the guide rod makes the spectrophotometer The wavelength repeatability during wavelength scanning is ±0.1nm or less. 8. The sinusoidal mechanism according to claim 6, wherein a bushing is also provided in the second through hole, and the cooperation between the bushing and the guide rod makes the spectrophotometer The wavelength repeatability during wavelength scanning is ±0.05nm or less.