JP2017219500A - Built-in weight lifting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a built-in weight lifting device that can use common components even if the size of a scale is different.SOLUTION: A built-in weight lifting device comprises: a cam shaft 12 to which the rotation force of a motor is transmitted and which rotates; a cam 121 which rotates together with the cam shaft; a movable part 13 which vertically moves with the rotation of the cam; a weight support arm 15 having a base part 151 installed to a groove 131 of the movable part freely detachably; a weight pressing plate 16 which presses a weight 14 which is elevated to a prescribed position while being supported by the weight support arm; a frame 17 which has a motor housing chamber 172, shaft support parts 175, 176 of the cam shaft, and guide parts 173, 173, 177 guiding vertical movement of the movable part; and a base 18 which has a frame fixing part 181 to which the frame is fixed by screws, and connection parts 182 which extend from the frame fixing part and are fixed to a base part of a weight measuring mechanism by screws. Even if the sizes of scales to which the weight is attached are different, components other than the weight 14, the weight support arm 15 and the base 18 can be commonly used.SELECTED DRAWING: Figure 8

Description

  The present invention lowers the weight built in the balance when adjusting the span of the balance and applies the load of the built-in weight to the load measurement mechanism. When the span adjustment is completed, the built-in weight is lifted away from the load measurement mechanism. With regard to the lifting device, the components of the built-in weight lifting device applied to different types of scales are shared.

Many of the high-performance balances have a built-in calibration weight as described in Patent Document 1 below, and have a known mass on a regular basis or when a balance user operates the switch. A weight is placed on a part of the load measuring mechanism, and the balance is calibrated.
The built-in weight lifting / lowering device is located inside the housing of the scale, and executes lifting / lowering of the built-in weight used for calibration.

JP 2009-121949 A

Since the built-in weight lifting / lowering device is arranged in the housing of the balance together with the load measuring mechanism, it is desirable that the built-in weight lifting / lowering device has a compact configuration in order to reduce the size of the balance.
Moreover, in order to obtain the merit of common parts, it is desirable that the components of the built-in weight lifting / lowering device attached to the scales having different weights and different sizes are made as common as possible.
In order to simplify the assembling process of the balance, it is desirable that the built-in weight lifting / lowering device can be retrofitted to a load measuring mechanism installed in the lower housing.

  The present invention was devised in consideration of such circumstances, and has a compact shape, and can be configured using a number of common parts even if the scale of the applied scale is different. An object of the present invention is to provide a built-in weight lifting / lowering device that can be retrofitted.

The present invention is a built-in weight lifting / lowering device disposed in a housing of a balance together with a load measuring mechanism, a motor, a camshaft that rotates by transmission of the rotational force of the motor, and a camshaft fixed to the camshaft. A rotating cam, a movable part that moves up and down with the rotation of the cam, and a base that is detachably attached to the movable part and supports a weight according to the movement of the movable part and moves up and down Up and down movement of the support arm, the weight holding plate that holds the weight supported by the weight support arm and raised to a predetermined position, the motor housing chamber that houses the motor, the shaft support portion that rotatably supports the camshaft, and the movable portion And a base having a frame fixing portion to which the frame is screwed and a coupling portion extending from the frame fixing portion and screwed to the base of the load measuring mechanism.
This built-in weight lifting / lowering device can be used in common for each component except the weight, the weight support arm and the base even if the scales to be mounted are different in size. Moreover, it can be retrofitted to the load measuring mechanism via the base.

Further, in the built-in weight lifting / lowering device of the present invention, the frame has a wall portion protruding upward and a boss having a screw hole protruding upward, and these constitute a guide portion. The movable part is provided with a hole through which each of the wall part and the boss is inserted.
In the built-in weight lifting / lowering device of the present invention, the first gear is mounted on the shaft of the motor housed in the motor housing chamber of the frame, and the second gear is mounted on the camshaft supported on the shaft support portion of the frame. The first gear and the second gear mesh with each other directly or via another gear, and the rotational force of the motor is transmitted to the camshaft.

  Further, in the built-in weight lifting / lowering device of the present invention, the weight holding plate is screwed to the screw hole of the boss of the frame.

  In the built-in weight lifting / lowering device of the present invention, the weight holding plate has a control board holding portion for holding the control board provided with the control circuit for motor control, and the control board is connected to the upper end of the wall portion of the frame and the control board. It is fixed by being sandwiched between the substrate pressing part.

  This built-in weight lifting / lowering device uses a small number of screws when assembling. That is, the only screws used are a screw for fixing the weight holding plate to the boss of the frame, a screw for fixing the frame to the base, and a screw for fixing the base to the base of the load measuring mechanism. Since fewer screws are used, the number of assembly steps can be reduced.

  The built-in weight lifting / lowering device of the present invention can be expected to reduce the cost of components and reduce the number of design steps by sharing the components. In addition, since fewer screws are used and retrofitting to the load measuring mechanism is possible, the assembly process can be simplified, and the manufacturing cost can be reduced.

The figure which shows the position in the scale housing | casing of the internal weight raising / lowering apparatus which concerns on embodiment of this invention. The figure which shows the built-in weight raising / lowering device and load measuring mechanism of FIG. Side view of the device of FIG. FIG. 2 is a perspective view of the built-in weight lifting / lowering device of FIG. The perspective view which changed the viewpoint of the built-in weight raising / lowering device of FIG. Plan view of the built-in weight lifting / lowering device of FIG. Side view of the built-in weight lifting / lowering device of FIG. 4 is an exploded perspective view of the built-in weight lifting / lowering device of FIG. The figure which shows the built-in weight raising / lowering apparatus and load measuring mechanism which concern on other embodiment of this invention. FIG. 9 is a perspective view of the built-in weight lifting device in FIG. FIG. 10 is an exploded perspective view of the built-in weight lifting device of FIG.

FIG. 1 shows a state in which a built-in weight lifting / lowering device 1 according to an embodiment of the present invention is arranged in a housing 40 of a scale. The built-in weight lifting / lowering device 1 is arranged to face the load measuring mechanism 30.
FIG. 2 shows the load measuring mechanism 30 and the built-in weight lifting / lowering device 1 taken out from the housing. FIG. 3 is a side view thereof.

A load of an object to be weighed placed on a weighing pan (not shown) is transmitted to the load transmission unit 31 of the load measurement mechanism 30 and the load measurement mechanism 30 measures the load.
A weight receiving arm 32 capable of supporting the inner weight 14 is fixed to the load transmitting portion 31 (FIG. 3), and the weight support arm 15 of the built-in weight lifting / lowering device 1 is lowered during calibration to support the weight. The inner partial copper 14 supported by the arm 15 is transferred from the weight support arm 15 to the weight receiving arm 32. When the calibration is completed, the weight support arm 15 moves up, receives the inner part copper 14 supported by the weight receiving arm 32, and lifts the inner part copper 14 to a height that does not contact the weight receiving arm 32.
The built-in weight lifting / lowering device 1 is responsible for raising and lowering the weight support arm 15.

FIG. 4 is a perspective view of the built-in weight lifting / lowering device 1. FIG. 5 shows a perspective view of the built-in weight lifting / lowering device 1 viewed from an angle different from that in FIG. 6 is a plan view and FIG. 7 is a side view. FIG. 8 is an exploded perspective view of the built-in weight lifting / lowering device 1.
The built-in weight lifting / lowering device 1 includes a pair of weight support arms 15 that support an internal weight 14, a weight support arm 15, a movable portion 13 that moves up and down together with the weight support arm 15, and a cam that contacts the movable portion 13. A camshaft 12 that rotates 121 to move the movable portion 13 up and down, a frame 17 that supports a motor that supports the camshaft 12 and applies a rotational force to the camshaft 12, and a frame 17 are fixed by screws 171. And a weight holding plate 16 for holding the inner weight 14 supported by the weight supporting arm 15 and a control board 19 provided with a control circuit for controlling the driving of the motor.

The frame 17 includes a motor housing chamber 172 that houses a motor. The opposite side wall 173 and side wall 174 of the motor storage chamber 172 protrude upward beyond the motor storage chamber 172, and a bearing hole 175 of the cam shaft 12 is provided in the protruding portion of the side wall 173, so that the side wall 174 protrudes. The portion is provided with a U-shaped hole 176 for bearing of the cam shaft 12.
The shaft 111 of the motor housed in the motor housing chamber 172 has a tip protruding from the side wall 173, the first gear 112 is fitted to the tip, and a tip protruding from the bearing hole 175 of the cam shaft 12. The second gear 122 is fitted to the part, and the first gear 112 and the second gear 122 are engaged with each other, and the rotational force of the motor is transmitted to the cam shaft 12.
A pair of bosses 177 protrudes upward from the frame 17. The boss 177 has a screw hole at the end surface, and the protruding height thereof is substantially the same as the protruding height of the side wall 173 and the side wall 174.

The movable portion 13 includes a frame covering portion 135 having a space into which the frame 17 enters, and an arm mounting portion 136 that extends from the frame covering portion 135 to the left and right and to which the weight support arm 15 is attached. The arm mounting portion 136 is provided with a groove portion 131 in which the base portion 151 of the weight support arm 15 is mounted. The frame covering portion 135 has a square hole 132 through which the side wall 173 of the frame 17 is inserted, and a side wall. A square hole 133 through which 174 is inserted and a round hole 134 through which boss 177 is inserted are provided.
The groove 131 of the arm mounting portion 136 is configured so that the base 151 of the mounted weight support arm 15 does not fall out from below. Further, the weight support arm 15 to be mounted in the groove 131 can be replaced if the base 151 has the same shape as the weight 151, and other weight support arms having different lengths for supporting the inner weight 14 can be exchanged. 15 can be mounted in the groove 131.
The side walls 173 and 174 of the frame 17 inserted into the square holes 132 and 133 of the frame covering portion 135 of the movable portion 13 and the boss 177 inserted into the round hole 134 are guide portions that guide the vertical movement of the movable portion 13. Playing a role.

The weight holding plate 16 is fixed to the upper end of the boss 177 by a pair of screws 161.
The weight holding plate 16 has a control board holding portion 162 that holds the control board 19. The control board 19 controls the weight holding plate 16 fixed to the upper ends of the side walls 173 and 174 of the frame 17 and the boss 177. It is sandwiched and fixed between the substrate pressing portion 162. Note that the upper and lower ends of the side walls 173 and 174 of the frame 17 are provided with irregularities that define the position of the control board 19.
The base 18 has a frame fixing portion 181 to which the frame 17 is fixed with a pair of screws 171 and a coupling portion 182 to which the base itself is fixed to the base portion of the load measuring mechanism 30 with screws 183 (FIGS. 2 and 3). doing. The frame fixing portion 181 is provided with a pair of convex portions 184 that fit into positioning holes 178 provided in the frame 17.

The built-in weight lifting / lowering device 1 is assembled as follows.
The motor is housed in the motor housing chamber 172 of the frame 17, and the cam shaft 12 to which the cam 121 is fixed is pivotally supported by the bearing hole 175 and the bearing U-shaped hole 176 of the frame 17.
Next, the first gear 112 is fixed to the tip of the motor shaft 111 protruding from the side wall 173 of the frame 17, the second gear 122 is connected to the tip of the cam shaft 12 that similarly protrudes, and the first gear 112 and teeth are fixed. Fix to fit.

Further, the base portion 151 of the weight support arm 15 is attached to the groove 131 of the arm attachment portion 136 of the movable portion 13 to fix the weight support arm 15 to the movable portion 13.
The side wall 173 of the frame 17 is passed through the square hole 132 provided in the frame covering portion 135 of the movable part 13, the side wall 174 of the frame 17 is passed through the square hole 133, and the boss 177 of the frame 17 is passed through the round hole 134. However, the movable portion 13 is lowered to a position where the frame covering portion 135 of the movable portion 13 covers a part of the motor accommodating chamber 172 of the frame 17 and the periphery of the cam 121 contacts the movable portion 13.

Next, the control board 19 is disposed so as to straddle the upper ends of the side wall 173 and the side wall 174 of the frame 17, and the control board pressing portion 162 of the weight pressing plate 16 is overlaid thereon, and the weight pressing plate 16 is paired with a pair of screws 161. To fix to the upper end of the boss 177.
By fixing with the screws 161, the frame 17, the control board 19, and the weight pressing plate 16 are integrated. And the movable part 13 with which the weight support arm 15 was fixed is integrated with this integrated structure in the state which can be moved up and down.
The integrated structure of the frame 17 incorporating the movable portion 13, the control board 19 and the weight holding plate 16 is coupled to the base 18 by fastening the frame 17 to the frame fixing portion 181 of the base 18 with screws 171.
The base 18 is fixed by fixing the coupling portion 182 to the base portion of the load measuring mechanism 30 with a screw 183 (FIGS. 2 and 3).

  In this built-in weight lifting / lowering device 1, when the radius at the contact position of the cam 121 that contacts the movable portion 13 increases as the cam shaft 12 rotates, the movable portion 13 rises and contacts the movable portion 13. When the radius at the contact position of the cam 121 decreases, the movable portion 13 descends. When the weight support arm 15 on which the inner weight 14 is placed descends from the position above the weight delivery position to the weight receiving arm 32 fixed to the load transmitting portion 31 and falls below that position, the inner weight 14 is Move to the weight receiving arm 32.

On the contrary, when the empty weight support arm 15 below the weight delivery position rises beyond that position, the inner partial weight 14 placed on the weight reception arm 32 moves toward the weight support arm 15.
Further, when the inner weight 14 placed on the rising weight support arm 15 comes into contact with the weight holding plate 16, the rising of the movable portion 13 stops. This is the state at the time of non-calibration.
Therefore, the inner partial copper 14 at the time of non-calibration is pressed by the weight pressing plate 16 and is in a state where it is not glazed.

When the built-in weight lifting / lowering device 1 is attached to a balance, the size of the inner weight 14 varies depending on the type of the balance. Therefore, it is difficult to use the weight support arm 15 that supports the inner weight 14 in various scales.
Similarly, the base 18 attached to the base of the load measuring mechanism 30 is difficult to use in common for various types of scales because the structure of the base of the load measuring mechanism 30 differs depending on the type of the scale.
However, other parts do not need to be changed even if the type of the balance is different, and can be used as a common part for the built-in weight lifting / lowering device.

9 shows a perspective view of the built-in weight lifting / lowering device 200 attached to the large load measuring mechanism 300, FIG. 10 shows the built-in weight lifting / lowering device 200 alone, and FIG. 11 shows an exploded perspective view thereof. .
In this built-in weight lifting / lowering device 200, a weight support arm 215 for supporting the inner weight 214 and a base 218 are used for a large scale, but the other weight holding plate 16, control board 19, movable part 13, frame 17 etc. use the same thing as FIG.

Thus, the built-in weight lifting / lowering devices 1 and 200 can be configured using many common parts, and the cost of the parts can be reduced and the number of design steps can be reduced.
In addition, the built-in weight lifting and lowering devices 1 and 200 have few screws used for assembly. When assembling an integrated structure of the frame 17 incorporating the movable portion 13, the control board 19 and the weight holding plate 16, only the screws 161 are used. Therefore, the number of assembling steps can be reduced, and the manufacturing cost can be reduced.
Further, since the built-in weight lifting devices 1 and 200 can be retrofitted to the load measuring mechanisms 30 and 300 attached to the lower housing 40, the assembly process can be simplified.

In addition, the structure shown here is an example, Comprising: This invention is not limited to it.
Here, the base 151 of the weight support arm 15 is attached to the groove 131 of the movable part 13 and the weight support arm 15 is fixed to the movable part 13, but the weight support arm 15 is fixed to the movable part 13 by other means. You may do it.
Also, means other than gears may be used to transmit the rotational force of the motor to the camshaft.
Further, the control board 19 may be arranged away from the built-in weight lifting / lowering device.

  The built-in weight lifting / lowering device of the present invention can be reduced in cost by sharing parts and simplifying the assembly process, and can be widely used in scales used in laboratories, universities, companies, and the like.

DESCRIPTION OF SYMBOLS 1 Built-in weight raising / lowering device 12 Cam shaft 13 Movable part 14 Inner part copper 15 Weight support arm 16 Weight holding plate 17 Frame 18 Base 19 Control board 30 Load measuring mechanism 31 Load transmission part 32 Weight receiving arm 40 Case 111 Motor shaft 112 1st Gear 121 cam 122 second gear 131 groove part 132 square hole 133 square hole 134 round hole 135 frame covering part 136 arm mounting part 151 weight support arm base 161 screw 162 control board pressing part 171 screw 172 motor housing chamber 173 side wall 174 Side wall 175 Bearing hole 176 U-shaped hole for bearing 177 Boss 178 Positioning hole 181 Frame fixing part 182 Coupling part 183 Screw 184 Convex part 200 Built-in weight lifting / lowering device 214 Internal copper 215 Weight support arm 218 Base 300 Load measuring machine Structure

Claims (5)

A built-in weight lifting / lowering device arranged in the housing of the scale together with the load measuring mechanism,
A motor,
A camshaft that rotates when the rotational force of the motor is transmitted;
A cam fixed to the camshaft and rotating together with the camshaft;
A movable part that moves up and down with rotation of the cam;
A weight support arm that has a base that is detachably attached to the movable part, and supports a weight in accordance with the movement of the movable part and moves up and down;
A weight holding plate for holding the weight that is supported by the weight support arm and raised to a predetermined position;
A frame having a motor housing chamber that houses the motor, a shaft support portion that rotatably supports the camshaft, and a guide portion that guides the vertical movement of the movable portion;
A base having a frame fixing portion to which the frame is screwed and a coupling portion extending from the frame fixing portion and screwed to the base of the load measuring mechanism;
A built-in weight lifting / lowering device comprising:   2. The built-in weight lifting / lowering device according to claim 1, wherein the frame includes a wall portion projecting upward that constitutes the guide portion, and a boss provided with a screw hole projecting upward, and the movable portion. The built-in weight lifting / lowering device is provided with a hole through which each of the wall portion and the boss is inserted.   2. The built-in weight lifting / lowering device according to claim 1, wherein a first gear is mounted on a shaft of the motor housed in a motor housing chamber of the frame, and the cam is pivotally supported by a shaft support portion of the frame. A second gear is mounted on the shaft, and the first gear and the second gear mesh with each other directly or via another gear, and the rotational force of the motor is transmitted to the cam shaft. Built-in weight lifting device characterized by that.   3. The built-in weight lifting device according to claim 2, wherein the weight holding plate is screwed into a screw hole of the boss of the frame.   5. The built-in weight lifting device according to claim 4, wherein the weight holding plate includes a control board holding portion that holds a control board provided with a control circuit for motor control, and the control board is provided on the frame. A built-in weight lifting and lowering device characterized by being sandwiched and fixed between an upper end of the wall portion and the control board pressing portion.