JPH01152318A - Built-in weight lift - Google Patents

Abstract

PURPOSE:To achieve a calibration easily and accurately, by lifting a built-in weight support member along a support pin with an axis center thereof being parallel with a load transmission shaft so that the center of applying a load coincides with the center of transmitting a load of an object to be measured. CONSTITUTION:A built-in weight support member 3 with a part thereof retained in contact with a cam is lifted or lowered by a built-in weight lifting mechanism using a cam mechanism. The built-in weight support member 3 is lifted along support pins 4a-4d with an axis center thereof parallel to a load transmission shaft 16 so that built-in weights 1 and 2 placed thereon are lifted being kept horizontal. Among floating frames 14, the height at which a light build-in weight 2 and a heavy built-in weight 1 are retained in contact is differentiated and when the built-in weights are lowered, first the light built-in weight 2 is placed on the floating frame 14, a condition under which a calibration is performed in a precision measuring mode. With a further lowering of the support member, the heavy built-in weight 1 is also placed on the floating frame 14 to perform a calibration in a large heavy measuring mode.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for lifting and lowering a calibration weight housed inside a weighing device, and particularly to a device suitable for lifting and lowering an annular calibration weight.

[Conventional technology]

As a weighing device is used for a long period of time, the weight display may become inaccurate due to slight loosening or slight deviation of the internal mechanism. A similar problem also occurs due to vibrations and the like when the weighing device is transported.

In this case, in order to calibrate the weight display of the weighing device to an appropriate value, it is necessary to adjust the display using a calibration weight whose exact weight is known in advance.

The most commonly performed calibration work has been a method of placing a calibration weight on a weighing pan. However, in this method, it is necessary to separately store a calibration weight in the weighing device, and to take out and use the calibration weight each time calibration is performed, which is inconvenient to handle. For this reason, a calibration weight is stored in the weighing device in advance, and when the need for calibration arises, the calibration weight is stored in the weighing device by operation from outside the device (hereinafter referred to as "built-in weight"). A mechanism is provided that performs calibration by transmitting a load to a load transmission section of a weighed object.

FIG. 5 shows the arrangement of built-in weights housed in an electromagnetic parallel weighing device (electronic balance) and its conventional lifting/lowering mechanism.

The reference numeral 50 in the figure is a built-in weight, and its planar shape is formed into an annular shape close to a perfect circle. The shape of the built-in weight is not necessarily specified, and various shapes such as horseshoe-shaped, rod-shaped, etc. are used depending on the arrangement of the internal mechanism of the weighing device, the structure of the built-in weight lifting mechanism, etc. .

However, as a result of testing built-in weights of various shapes, the inventors have already confirmed that a ring-shaped calibration weight is the best in terms of ease of calibration work and accuracy of calibration.

That is, if the built-in weight 50 is arranged so that the axis of the support shaft of the weighing pan 51, that is, the axis for load transmission, and the center of the annular built-in weight 50 are aligned, the load of the built-in weight 50 can be transferred to the beam (weighing object). The load can be applied to the member (53) that transmits the load to the weighing mechanism without displacing it from the axis of the support shaft 52. Therefore, even when the load of the built-in weight is applied, no special stress is generated on the floating frame, and there is an advantage that calibration can be easily performed without performing adjustment work such as adjusting the four corners.

Next, reference numeral 54 is a lifting plate for lifting and lowering the built-in weight, and the cam 5
5, the built-in weight support section swings in the X-Y direction about the fulcrum 54a.

In this conventional configuration, in a normal weighing process, the lifting plate 54
The built-in weight support part of is raised and fixed in the X direction, and the floating frame 5
3 so that the load of this built-in weight 5o is not applied. When the need for calibration arises, the cam 55 is rotated to lower the built-in weight support portion of the elevating plate 54 in the Y direction, and the built-in weight 50 is placed on the floating frame 53 to perform calibration.

[Problem that the invention seeks to solve]

Although the device with the above configuration has good performance, it also has the following problems, and it is actually extremely difficult to ensure higher calibration accuracy and realize easier calibration work, Development of a mechanism is required.

In the device configured as described above, (1) First, in a state where weighing is possible, the built-in weight is raised by the lifting plate 54, and a part of it is stored in a recess in the floor plate 56 of the weighing chamber in the weighing device main body. The situation is as follows. In this state, the weighing device is rearranged, transported, etc., but at that time, the built-in weight 50 may shift from a predetermined position due to vibration or inclination. In such a situation, it becomes impossible to perform accurate calibration during calibration, and depending on the case, there is a risk of damaging the internal mechanism of the weighing device, such as the floating frame.

Incidentally, if the weighing device is transported with the built-in weight 50 placed on the floating frame 53, a load many times the weight of the built-in weight will be instantaneously applied to the floating frame due to vibrations, etc., and the weighing mechanism connected to the floating frame will be damaged. There is a risk of destroying it. Therefore, this method is absolutely impossible.

(2) In addition, the lifting plate 54 supporting the load of the built-in weight 50 may be bent due to the inertia caused by the vibration during transportation, as described above.
There is also a possibility that the lifting mechanism may be damaged due to the large stress applied to the cam 55 and the fulcrum 54a.

(3) Furthermore, since the built-in weight 50 is lifted and lowered by the lifting plate 54 that swings around the fulcrum 54a, the built-in weight 50 is actually lifted and lowered along the axis of the support shaft 52. Instead, a circular arc is drawn with the fulcrum 54a as the center. As a result, the support shaft 5 is placed on the floating frame 53.
In order to accurately align the axis of the weight 2 and the center of the built-in weight 50, it is necessary to configure the built-in weight lifting mechanism with great precision.

(4) Recently, it is also possible to switch to a multi-step weighing mode with a - machine, such as a weighing mode in which the maximum weighing capacity is lower but the minimum scale is smaller, and a weighing mode in which the minimum scale is larger but the maximum weight is larger. Although there are devices that can do this, each of these devices requires a built-in weight that corresponds to the mode. However, in the conventional mechanism, there is no device that accommodates a plurality of built-in weights, and therefore there is no mechanism for raising and lowering a plurality of built-in weights corresponding to each mode.

[Means for solving problems]

The present invention has been constructed in view of the above-mentioned problems, and includes a support member that supports a plurality of built-in weights and moves the built-in weights up and down along the axial direction of a load transmission shaft such as a weighing pan support shaft; This built-in weight lifting/lowering mechanism is configured to have a mechanism for lifting and lowering the built-in weight supporting member, and a means for sequentially placing each built-in weight on a floating frame when there is a plurality of built-in weights.

[Effect]

The built-in weight lifting mechanism using the cam mechanism lifts and lowers the built-in weight supporting member whose negative portion is in contact with and latched to the cam. The built-in weight support member moves up and down along a support pin whose axis is parallel to the load transmission axis, thereby moving up and down while holding the built-in weight placed therein in a horizontal state. By differentiating the heights at which the lightweight built-in weights and the heavy built-in weights contact and engage in the floating frame, when each built-in weight is lowered, the light weight built-in weights first touch the floating frame i! 3i placed,
In this state, perform calibration in precision measurement mode.

Further, when the support member is further lowered, the large built-in weight is also placed on the floating frame, and calibration in the large weight measurement mode is performed.

〔Example〕

An embodiment of the present invention will be described in detail below with reference to the drawings.

FIGS. 1 and 2 specifically show the built-in weight lifting device.

In the figure, reference numeral 1 indicates a large (heavy) built-in weight, and 2 indicates a small (light) built-in weight. As is clear from the figure, the built-in weights 1 and 2 are formed into planar annular shapes, and are arranged concentrically by support members to be described later. 3 is a support member that supports these built-in parts w41 and w41 and raises and lowers them. Reference numerals 3a, 3b, and 3C designate built-in weight support arms of the support member 3 that extend from the U-shaped support member frame 3d into the frame. The built-in weights 1 and 2 are supported by the support arms 3a, 3b, and 3c, so that they are arranged in concentric circles so that their centers are common, and the common centers transfer the load of the object to be weighed to the beam side. The center of the load transmission shaft is aligned with the axis of the load transmission shaft.

Next, support pins 4a are provided at the four corners of the frame 3d of this support member.
4b, 4c, and 4d are inserted. The lower end of this pin is fixed to the weighing device main body, and the support member 3 is attached to each built-in weight 1 along the axis of the load transmission shaft.
．． 2 is raised and lowered while being held horizontally. 3e and 3f are elevating protrusions protruding from opposing sides of the frame 3d, each elevating protruding piece 3e,
The support member 3 and the built-in weights 1 and 2 supported by the support member 3 are raised and lowered by the lifting mechanism coming into contact with 3f.

Next, a mechanism for raising and lowering the support member will be explained.

5 is a rotating shaft rotated by a gear motor, and a first cam 7 and a second cam 8 are provided to this rotating shaft 5. Further, reference numeral 9 is a bearing fixed to the weighing device main body side. Of the two cams provided on the rotating shaft 5, the first cam 7
is in contact with the lower surface of the lifting protrusion 3f of the support member 3,
Another second cam 8 is in contact with the lower surface of one end of the first swing plate lO, which forms a part of the elevating motion transmission mechanism. This rocking plate 10
is designed to swing in the X1-Y1 direction by a fulcrum 11. Next, 12 is arranged so as to be approximately perpendicular to this first rocking plate 10, and with a fulcrum 13, X2-
The second swing plate is configured to swing in the Y2 direction, and the end of the second swing plate that contacts the first swing plate is arranged so as to be in contact with the lower surface of the first swing plate 10.

FIG. 3 omits the built-in weight lifting mechanism and shows the positional relationship between the built-in weights 1 and 2 and the floating frame for load transmission. 14 in the diagram
indicates a floating frame, 14a is a notch for mounting and supporting a large built-in weight l formed in this floating frame 14, and 14b
is a notch for mounting and supporting the small built-in weight 2. Among these notches, the bottom of the notch 14b that supports the small built-in weight 2 is formed higher than the notch 14b for the large built-in weight by h.

Next, the operating state will be explained.

First, a state in which the built-in weights 1 and 2 are raised and no load is applied to the floating frame, that is, a state in which the weighed object can be measured will be described.

By operating the gear motor, the first and second cams 7 and 8 are rotated via the rotating shaft 5. First of all
Referring to the cam 7, as the first cam 7 rotates, the protrusion 3f that contacts the cam 7 is pushed upward in the X3 direction. Similarly, one of the ends of the elevating motion transmission mechanism pushes up the cam contact end of the first rocking plate lO that contacts the second cam 8. As a result, the opposite end becomes X1 with the fulcrum 11 as the center.
direction, and push down the end of the second swing plate 12 in the same direction. As a result, the end of the second rocking plate 12 on the protruding piece 3e side rises in the X2 direction, pushing this protruding piece upward in the same direction. That is, the rotation of each cam 7.8 pushes up each projection 3e, 3f at the same time. This operation causes the support member to move to each pin 4a to 4d.
The built-in weights 1 and 2 supported by this support member rise while maintaining a horizontal state. Next, the rotation of the cam is stopped in the upper bound state, and each built-in weight is supported.

As a result, all the loads of the visceral bones w41 and 2 are supported by the support member 3, and only the load of the object to be weighed placed on the weighing pan 15 is transmitted to the floating frame 14. Note that the reference numeral 16 in FIG. 4 is a support shaft that supports the weighing pan 15, and is a load transmission shaft that transmits the load of the weighed object.

Next, the operating state when performing calibration will be explained.

By operating the gear motor, each of the first and second cams 7.8 is rotated again. As a result, the support member 3 gradually descends by an operation opposite to the above-mentioned ascending operation. As a result of this lowering, when the position of the support surface SL (see FIG. 6) of each built-in weight 1 and 2 reaches the position Ll shown in FIG. Crack 1
4b, and the load of this weight 2 is transmitted to the floating frame 14. Furthermore, the support member 3 is lowered to support the support surface S.
When the position of L reaches the position of L2, the large built-in weight l is placed in the notch 14a of the floating frame 14, and the loads of both weights l and 2 are transmitted to the floating frame 14. .

Here, when calibrating the precision weight measurement mode of the weighing device, the positions of the support surface SL of the support member 3 are adjusted to Ll and L2.
Only the small built-in weight 2 is placed on the floating frame 14 between the two. As a result, accurate calibration can be performed using the small built-in weight 2 having a weight suitable for calibration in the precision weight measurement mode. When performing calibration in the large weight measurement mode, the support member is lowered so that the support surface SL is below the position L2, and the calibration is performed using the total load of the small built-in weight 2 and the large built-in weight 1. During the above operation, each built-in weight l
and 2 and the axis of the load transmission shaft 16 are always aligned, so placing a calibration weight will not apply any special stress to the floating frame, and accurate calibration can always be performed. .

The configuration of the present invention has been explained above using an example in which two types of built-in weights, a large built-in weight and a small built-in weight, are raised and lowered. It goes without saying that the technical configuration of the present invention also includes a configuration in which the components are sequentially placed on the floating frame.

〔effect〕

The built-in weight lifting mechanism raises and lowers the built-in weight support member, and the built-in weight support member moves up and down along the support bin whose axis is parallel to the load transmission axis, thereby bringing the placed built-in weight into a horizontal state. Go up and down while holding it. Therefore, when the built-in weight is placed on a load transmission section such as a floating frame, the center of load application and the center of load transmission of the weighed object coincide, making it possible to perform calibration easily and very accurately.

In addition, since the support member is supported by multiple strong support arms, the built-in weight can be held securely even if vibration or large stress is applied when the weighing device is moved, resulting in injury to the internal mechanism of the weighing device. There is no risk of giving.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a built-in weight lifting device showing an embodiment of the present invention, Fig. 2 is a plan view of the built-in weight lifting device housed in a weighing device, and Fig. 3 shows the built-in weight and floating frame. Figure 4 is a plan view of the built-in weight and floating frame showing the arrangement of the figure A in Figure 3.
5 is a side view of a lifting mechanism showing a conventional built-in weight lifting mechanism, and FIG. 6 is a sectional view showing a state in which the built-in weight is placed on an arm of a built-in weight support member. l...Large built-in weight 2...Small built-in weight 3...
・Built-in weight support members 3a, 3b, 3c...Support member arm 3d...Support member frame 3e, 3r...Protrusions for lifting and lowering the support member 4a, 4b, 4b...Bin 5 for supporting the support member ... Rotating shaft 6 ... Geared motor 7 ... First cam 8
...Second cam lO...First tl moving plate 12...
・Second rocking plate 14...Floating frame 16...Load transmission shaft Fig. 3C Fig. 4 Fig. 5 Fig. 3b (3)

Claims (3)

[Claims] (1) In a weighing device that calibrates the weighing device by applying the load of the built-in weight to the load transmission part of the weighing device, the built-in weight is supported in an annular shape, and A built-in weight lifting device comprising a built-in weight support member configured to move up and down, and a lifting mechanism that moves the internal weight support member up and down. (2) The number of annular built-in weights supported by the built-in weight support member is two or more, and the height of the built-in weight mounting surface in the load transmission section of the weighing device is configured to be different for each weight, and calibration is performed. The built-in weight elevating device according to claim 1, characterized in that the built-in weights are sequentially placed on the load transmission section in accordance with the load measurement mode to be used. (3) The built-in weight support member lifting mechanism is a cam mechanism,
The cam mechanism includes a first cam that contacts a protrusion formed on the support member, and a vertical motion transmission mechanism that is coaxial with the first cam and forms a part of the vertical motion transmission mechanism. Consisting of a first rocking plate and a second cam in contact with the
The elevating motion transmission mechanism is composed of the first swing plate and a second swing plate that engages with and swings from the first swing plate, and the elevating motion transmission mechanism is configured to move up and down by the rotation of the first cam transmitted to the protrusion. Claim 1 is characterized in that the built-in weight support member is raised and lowered by the movement and the lifting movement caused by the rotation of the second cam which is transmitted to another projecting piece via the lifting movement transmission mechanism. Built-in weight lifting device as described in ).