JPH0533034U - Built-in weight removal device - Google Patents

Abstract

(57) [Summary] [Purpose] The built-in weight of the weighing device properly locks the built-in weight without fine adjustment of the mechanism. [Structure] A weight lifting plate 10 having elasticity by the rotation of a cam 12 of a rotary shaft 3 rotated by a geared motor 6 swings around fulcrums 10a and 10b, and a built-in weight 11 moves up and down corresponding to this swing. . Similarly, the rotary shaft 19 rotates in synchronization with the rotary shaft 3 via the belt 26, and the operation of the cam 22 of the rotary shaft 19 causes the weight lifting plate 18 to lift another built-in weight 23. In particular, when the built-in weights 11 and 23 are raised, the built-in weights are locked to the locking plate provided on the partition plate 27, and the weight lifting plates 10 and 18 have elasticity at the time of this locking plate. Therefore, due to this elasticity, the built-in weight is pressed against the locking plate with an appropriate pressure.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a built-in weight adding / removing device in an electronic scale, and more particularly to a device suitable for adding / removing a calibration weight contained in an electromagnetic balance type weighing device.

[0002]

[Prior Art]

 High-precision electronic balances such as electromagnetic balance type electronic balances are measured by extremely small expansion and contraction of the load transmission mechanism due to environmental changes in the environment such as temperature and humidity, and changes in conductivity of the electromagnetic section. Accuracy changes. For this reason, there is provided a weighing device that incorporates a calibration weight and a device that adds and removes this weight to and from the load transfer mechanism, and that performs calibration appropriately by an external operation of the device or by automatic operation of the balance. ing.

[0003]

[Problems to be solved by the device]

 It is natural that the above built-in weight adjusting device is required to have certainty of operation and durability from the original purpose of installation of the device, but this is not always sufficient. That is, since the weight incorporated in the weighing device is a relatively heavy object, when the weighing device is moved, the built-in weight may drop from a predetermined location and damage other mechanisms, or the built-in weight itself may be damaged. It is also necessary to take care so that no problems occur.

As one of the devices for removing the built-in weight, there is, for example, Japanese Utility Model Laid-Open No. 63-137827. This device is configured to actuate a lifting tray (a member for raising and lowering a built-in weight) by driving two levers with springs, and the built-in weight is appropriately added to and removed from the load transmission mechanism by the operation of the lifting tray. ing. Although this device has a relatively simple mechanism and can be made small, the following problems are expected.

First, when the built-in weight is not used, it is necessary to raise the built-in weight by the addition / removal device so that the load is not applied to the load transmission mechanism side of the weighing device. The built-in weight is clamped by the lifting pan and the notch placed on the upper part of the built-in weight so that the built-in weight does not fall off when moving the weighing device. Originally, the distance that the built-in weight ascends and descends is small (for example, about 2.5 mm), but when the built-in weight rises, this built-in weight does not fall off and it is not too strongly pressed against the notch or the lifting tray. It is necessary to finely adjust the installation height of this lifting tray and the position of the lever that contacts the lower surface of the lifting tray, which requires time and skill when manufacturing the device.

Further, since the drive source of the device is a spring, there is a possibility that the device may malfunction due to a decrease in elasticity of the spring when used for a long period of time, so-called “settling”.

[0007]

[Means for Solving the Problems]

 The present invention is a built-in weight removing device that solves the above-mentioned problems, in which an elevating member that operates using an electric motor or the like as a drive source and that moves up and down the built-in weight is formed of an elastic material, for example, an elastic plate. The built-in weight removing device is configured to sandwich the built-in weight by the built-in weight lifting member and a locking member, which is a built-in weight receiving portion arranged so as to face each other via the built-in weight, when the weight is raised.

[0008]

[Action]

 Since the elevating member is formed of an elastic plate, when the built-in weight is lifted and the built-in weight is clamped together with the built-in weight receiving portion, the elevating member is appropriately deformed by its elasticity. That is, the built-in weight is clamped and fixed with an appropriate clamping force by the elastic plate serving as the lifting member and the locking plate serving as the built-in weight receiving portion even if the height of the lifting member is not finely adjusted.

[0009]

【Example】

 Embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, and is a plan view of the built-in weight removing device with the built-in weight locking plate located above the built-in weight removed. This device is directly driven by a driving device such as an electric motor and raises and lowers one of the two built-in weights, and a driving force transmission means such as a transmission belt for the lifting mechanism 1. And a second elevating mechanism 2 that is connected to the first elevating mechanism 1 to elevate the other built-in weight by interlocking with the first elevating mechanism 1.

First, the configuration of the first lifting mechanism will be described. Reference numeral 3 is a rotary shaft that is rotatably supported by bearings 4 and 5, and a geared motor 6 is arranged at one end thereof as a drive source. Reference numeral 7 denotes a fin support member arranged with respect to the rotary shaft 3, and the fin support member 7 is provided with fins 8 projecting in the cross direction as shown in FIG. In this way, the position sensor 9 including, for example, a photo sensor is arranged.

Reference numeral 10 denotes a weight lifting plate as a weight lifting member, one end of which is located under the rotary shaft 3 and the other end of which is located under one built-in weight 11. Further, fulcrums 10a and 10b are continuously provided on both side edges of the weight lifting plate 10, and the ends of the fulcrums 10a and 10b are bolts or the like with respect to a mounting portion 30 projectingly arranged on the weighing apparatus main body. It is attached by attaching means. As a result, the weight lifting plate 10 can swing about the fulcrums 10a and 10b. The weight lifting plate 10 is made of a material having sufficient strength to support the load of the built-in weight and having elasticity as a whole. Reference numeral 12 is a cam provided on the rotary shaft 3 and in contact with the weight lifting plate 10.

Reference numeral 13 is an arm, which is one of the load transmitting members of the electromagnetic balance type weighing device, and 14 is a pipe for mounting the weighing pan which is erected on this arm. Weight mounting members 15a and 15b are fixed to both sides of the arm 13, centering on the installation portion of the pipe 14 for weighing plate. In addition, a Roberval mechanism 17 is connected to the end of the arm 13 opposite to the side where the weighing pan mounting pipe 14 and the weight placing members 15a and 15b are installed via a floating frame 16 so that the weighing pan is loaded. The load is transmitted via the arm 13 to a load measuring mechanism (not shown) guided by the Roberval mechanism 17.

Next, the second lifting mechanism 2 also has basically the same structure as the first lifting mechanism. That is, reference numeral 18 denotes a weight lifting plate made of the same material as the weight lifting plate 10 and can swing about fulcrums 18a and 18b continuously provided on both side edges. Further, the built-in weight 23 having the same structure as the built-in weight 11 is configured to be lifted and lowered by the weight lifting plate 18, and is adapted to be locked to the weight mounting member 15b provided on the arm 13. There is.

Reference numeral 19 denotes a rotary shaft that is rotatably supported by bearings 20 and 21, and a cam 22 is attached to the rotary shaft 19. Further, a pulley 24 is attached to one end of the rotary shaft 19, and a pulley 25 is also provided at the end of the rotary shaft 3 of the first elevating mechanism 1, and a belt 26 is attached to these pulleys 24 and 25. It is arranged so that the rotational force on the shaft 3 side is transmitted to the shaft 19.

FIG. 3 shows an example of the configuration of the cams of the first and second weight lifting mechanisms. Although the cams 12 and 22 provided on the rotary shafts 3 and 19 are configured to rotate at the same angular velocity as shown in the figure, their shapes are different. As a result, each time the rotations of the rotary shafts 3 and 19 change by about 90 °, the combination of the cam operations is different. As a result, by adjusting the rotation angle of each rotary shaft, it is possible to select the operation pattern of raising only one built-in weight, raising both built-in weights, or both built-in weights. Further, this operation pattern can be automatically controlled by detecting the rotation angle of the rotary shaft 3 by the position sensor 9 shown in FIG. Because the diameter of the pulley 24 provided on the shaft 19 is exactly the same as the diameter of the pulley 25 of the shaft 3, the shaft 19 rotates in synchronization with the shaft 3.

A partition plate 27 is arranged so as to cover the built-in weights 11 and 23 centering on the upper portion of the pair of built-in weights 11 and 23 of the built-in weight lifting mechanism having the above-described configuration. Legs 27a (see FIGS. 1 and 2) are arranged at the four corners of the partition plate 27, and the partition plate 27 is fixed to the floor surface of the weighing device by the four legs 27a. In FIG. 2, on the back surface of the partition plate 27, that is, on the surface facing the built-in weights 11 and 23, a locking plate 28 as a locking member is provided so as to be orthogonal to the partition plate 27.

Next, the operating state of the above-mentioned device will be described.

When using the weighing device, the loads of the built-in weights 11 and 23 are not applied to the measuring mechanism side. That is, in FIG. 2, the cam contact portion of the weight lifting plate 10 is lowered as shown in FIG. 2 by the rotation of the cam 12, and the other end is raised about the fulcrum portions 10a and 10b as a result, and the built-in weight 11 is raised. Let When the built-in weight 11 rises, the constricted portion 11a and the thin shaft portion 11b at the rear end of the built-in weight 11 are fitted and locked in the groove portions of the respective locking plates. This state will be described by taking the engagement state in the constricted portion 11a as an example as shown in FIG. 2, and the constricted portion 11a is pressed and locked by the groove 28a formed in the locking plate 28. In this case, since the weight lifting plate 10 is made of an elastic material, the built-in weight 11 is pressed against the locking plate 28 side by the elasticity of the weight lifting plate 10, so that the mounting height of the weight lifting plate 10 is not enough. Even if it is not adjusted slightly, the elasticity of the elevating plate 10 causes the built-in weight 11 to be pressed and fixed to the locking plate 28 side with an appropriate pressure.

Weight measurement work is performed while the built-in weight is raised, and the weighing device is also moved. In particular, when the device is moved, the device may be dropped and a large impact may be applied to the built-in weight placement portion. In such a case, the weight lifting plate 10 having elasticity absorbs this impact and It can function to prevent adverse effects on the mechanism of. Although not shown, it goes without saying that the second built-in weight raising / lowering mechanism 2 side also works exactly the same when the weight is raised.

Next, by rotating the cam 12 to lower the built-in weight 11, the built-in weight 11 is placed (locked) on the weight placing member 15 a, and the weight thereof is the load of the weighing device via the arm 13. It is transmitted to the transmission mechanism side for calibration. By adjusting the rotation angles of the cams 12 and 22 as shown in FIG. 3, it is possible to control the load of both built-in weights or the load of only one built-in weight. ..

[0022]

[Effect of the device]

 According to the present invention, as described in detail above, since the weight raising / lowering member that causes the weight to directly perform the raising / lowering operation is made of an elastic material, the elasticity allows fine adjustment of the mounting position of the weight raising / lowering member. Since the weight is pressed against and fixed to the locking member on the upper side, fine adjustment of the mounting height of the weight lifting / lowering member becomes unnecessary, and the steps in the assembly work of the device can be reduced.

Further, even when a large load is applied to the weighing device during transportation of the weighing device, this load can be absorbed by the elasticity of the weight elevating / lowering member, and the adverse effect of the large load is exerted on other parts of the device. Can be prevented.

[Brief description of drawings]

FIG. 1 is a plan view of a built-in weight removing device according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a schematic view showing an operating state of a device by cams in the first and second lifting mechanisms.

FIG. 4 is a diagram showing an angle detection state by a sensor that detects a rotation angle of a rotation shaft.

[Explanation of symbols]

 1 First Elevating Mechanism 2 Second Elevating Mechanism 3 Rotating Shaft 6 Geared Motor 9 Position Sensor 10 Weight Elevating Plate (Weight Elevating Member) 11 Built-in Weight 12 Cam 13 Arms 15a, 15b Weight Placement Member 18 Weight Elevating Plate 19 Rotating Axis 22 Cam 23 Built-in Weight 24, 25 Pulley 26 Belt 27 Partition Plate 28 Locking Plate (Locking Member)

Claims (3)

[Scope of utility model registration request] 1. A device for adding and removing a built-in weight to and from a load transmission mechanism of a weighing device, which is arranged below the built-in weight and moves up and down by swinging movement of the built-in weight, and a built-in weight. And a locking member which is disposed on the upper part of the weight and which receives and locks the built-in weight when the built-in weight rises, the weight lifting member is formed to have elasticity, and the raised built-in weight has elasticity to the locking member. A built-in weight removing device, which is configured to be sandwiched by a weight lifting member. 2. A first and second elevating mechanism, wherein the first elevating mechanism is a rotary shaft rotated by a drive source such as an electric motor, a cam provided on the rotary shaft, and a rotation of the cam. And a rotating shaft that rotates in synchronism with the rotating shaft of the first elevating mechanism by the power transmission means. 2. The built-in weight according to claim 1, further comprising: a cam provided on the rotary shaft; and a weight lifting member that rocks by the rotation of the cam and lifts and lowers another built-in weight by this rocking motion. Addition and removal device. 3. A sensor for detecting a rotation angle of the rotation shaft of any one of the rotation shafts of the first and second lifting mechanisms is arranged, and the rotation angle of the rotation shaft is controlled by this sensor. The built-in weight removing device according to claim 2, wherein