JPH11108748A - Weighing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent tare from oscillating at the time of weighing and to conduct weighing rapidly and accurately without being affected by link parts of the tare to related members, in the weighing device for weighing end-part weight of a weighed article by using the tare hung from two weighing instruments and adapted to support two points of the weighed article in a bridging manner. SOLUTION: This weighing device has two tares 5A, 5B respective tare parts have vertical arms 5A1, 5B1 hanging down from weighing instruments 3A, 3B via hang-down members 4A, 4B and weighed-article support arms 5A2, 5B2 extending horizontally from the vertical arms. The two weighed-article support arms are disposed to confront each other for supporting a weighed article W between the support arms in a bridging manner, the two vertical arms and the hang-down members are connected by connection means 4A5, 4B5 hardly giving frictional force to their relative movement to each other, and the two vertical arms are connected to still-holding members 7A, 7B each situated on the lateral side thereof by link mechanisms 6A, 6B allowing the respective vertical arms to move vertically without frictional force.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a weighing apparatus suitable for weighing, for example, a connecting rod, which is an engine part, and more particularly to a structure of a tare portion of a weighing apparatus for hanging weighing.

[0002]

2. Description of the Related Art Connecting rods are required to be well-balanced without vibration or the like as the engine becomes more sophisticated, so that large and small end weights must be accurately weighed. Conventionally, an apparatus shown in FIG. 3 has been used to weigh these large and small end portions. In this conventional apparatus, a C-shaped tare 56 hung from hanging weighing hooks of two weighing scales 52 and 53 mounted on a plate 51 supported by supporting legs 50 via hanging springs 54 and 55 is provided. A pair of opposed weighing object support arms 57, 58 provided at the lower end of the C-shaped tare 56.
Have positioning pins 59, 60 at their distal ends, and the positions of these positioning pins are aligned with the vertical positions of the corresponding suspension springs 54, 55, respectively. The weighing object W positioned by these positioning pins and placed in a bridge between the support arms 57 and 58, for example, the large end weight and the small end weight of the connecting rod are weighed and displayed by weighing meters 52 and 53, respectively. You.

[0003]

When weighing, the support arm 5 is required.
In order to prevent the tare 56 from swaying due to the movement of the center of gravity when the weighing object is placed on the
A swing prevention device is provided below 7, 58. This anti-sway device comprises, for example, oil tanks 61 and 62 filled with oil, and slope bodies 63 and 64 having one ends connected to support arms 57 and 58 and the other ends immersed in oil in the oil tank. . However, such an anti-sway device takes a long time to stabilize, so that the time required for weighing is relatively long, so that there is a problem that rapid weighing cannot be performed.

Further, in the case of a conventional weighing device, at the connection between the suspension springs 54, 55 and the C-shaped tare 56 or at the connection between the suspension spring and the underfloor weighing hook, the above-mentioned weighing device is used. As a result of the movement of the center of gravity, a force other than the vertical direction acts, and there is a problem that a stable weighing result cannot be obtained.

[0005] Accordingly, an object of the present invention is to provide a weighing device which can obtain a stable weighing result with a short weighing time.

[0006]

According to the first aspect of the present invention, the above object is attained as follows. That is,
The weighing hooks of the two weighing scales juxtaposed at intervals have two tares suspended via suspending members, respectively. Each tare is connected to the suspending member. A vertical arm that hangs down and a weighing object support arm extending laterally from the vertical arm, the two weighing object support arms substantially supporting the weighing object in a bridge state between the supporting arms. Are arranged opposite to each other at the same height position, and the two vertical arms and the hanging member are connected by a connecting means having a small frictional force with respect to their mutual movement. It is connected to the fixed holding member on the side by a low-friction motion link mechanism which allows substantially only vertical movement of each longitudinal arm.

According to this configuration, when the weighing object is placed between the support arms in a cross-linked state during weighing, the lateral movement of the tare is regulated by the linked link mechanism even if the center of gravity moves, and the sway of the tare is caused. Is suppressed, the state of the weighing device is stabilized within a short time, and measurement in a preferable state is immediately performed. At this time, since the two vertical arms and the hanging member are connected by a connecting means that does not substantially generate a frictional force with respect to their mutual movement, the vertical arm and the hanging member are transmitted corresponding to the weight of the weighing object. This does not cause a situation in which a part of the force applied to the weighing hook is deviated from the direction toward the weighing hook, and provides an advantageous effect that stable and accurate measurement results are obtained. Also, regardless of where the load of the weighing object is applied on any part of the supporting arm, the load on the weighing scale is the same, and therefore, it is possible to cope with various weighing objects having different sizes.

According to the second aspect of the present invention, the connecting means between the two vertical arms and the suspension member is a spherical plain bearing,
Each of the link mechanisms has upper and lower two levers for connecting between the tare vertical arm and the stationary holding member, and each fulcrum position is set such that a straight line connecting the fulcrum of each of the connecting portions is a parallelogram. It is determined, and each fulcrum is constituted by a ball bearing. The connection means is composed of a spherical plain bearing with small frictional resistance, and the fulcrum of each coupling part of the link mechanism formed in a parallelogram is composed of a ball bearing with small frictional resistance, so that the tare is simple. And the effect that the weight of the weighing object applied to the tare is reliably transmitted to the weighing hook without being disturbed by the link mechanism.

According to the third aspect of the present invention, the weighing object support arm of each tare has a positioning pin and a support roller provided at a weighing object support position, and both support rollers are arranged in parallel with each other. And are supported by bearings. Therefore, since the weighed object is supported on the support roller that is supported by the bearing having a small frictional resistance, even if a deviation occurs between the weighed object and the support roller when setting the weighed object,
The force due to the displacement is released by the rotation of the support roller, and the influence on the weighing is reduced.

According to the fourth aspect of the present invention, the positioning pin and the supporting roller are mounted on the supporting plate, and the supporting plate is placed and fixed on the weighing object supporting arm via the height adjusting plate. Therefore, the positions of the positioning pin and the support roller can be easily changed and adjusted in accordance with the size of the weighed object.

According to the fifth aspect of the present invention, there is provided a cassette for mounting the weighing material, and the cassette movably supports the cassette on the upper surfaces of the weighing material support arms of both tare containers. Cassette supporting roller, and a pin hole that fits into a cassette positioning pin provided on the weighing object support arm, so that a dedicated cassette is placed on the weighing object support arm for each weighing object having a different size and shape. It can be mounted simply and without frictional contact with the weighing object support arm, so that a changeover corresponding to the weighing of different weighing objects can be quickly dealt with.

[0012]

FIG. 1 shows an embodiment of a weighing device according to the present invention. The weighing device includes an upper plate 2A fixed to the upper ends of a pair of right and left columns 1A and 1B in a cantilever manner. It has weighing devices 3A and 3B mounted on the weighing device 2B, and tares 5A and 5B are suspended from under-floor weighing hooks 3A1 and 3B1 provided on the respective weighing devices via suspension members 4A and 4B. Has been lowered.

The left and right tares and the members associated therewith have the same configuration. Therefore, taking the left side configuration as an example, the hanging member 4A for suspending the tare 5A will be described.
Is a hook 4A which is engaged with the weighing hook 3A1 under the floor.
1, a screw rod 4A3 connected to the tare 5A, an upper flange plate 4A5 screwed to the screw rod 4A2, and a lower flange plate 4 screwed to the screw rod 4A3.
A5 and spacer 4A6 interposed between both flange plates
The flange plate 4A4 and the spacer 4A6 are provided with holes for inserting the fixing bolts 4A7, and the lower flange plate 4A5 is provided with screw holes for the bolts 4A7. . In order to adjust the height of the tare 5A by the height adjusting device, first, the members except for the bolt 4A7 are combined in the arrangement as shown in the drawing, and then the flange plate 4A4 is rotated with respect to the screw rod 4A2, or The flange plate 4A5 is rotated with respect to 4A3, or both are rotated to position the two flange plates, and the lock nuts 4A8 and 4A9 fix the positions of the flange plates 4A4 and 4A5 with respect to the threaded rods 4A2 and 4A3. next,
The bolts 4A7 are inserted and tightened to make the entire member integral. Then, fulcrums 6A3 and 6A6 (or 6A
4, 6A5) is measured and the difference between the two height positions is determined. This difference is determined by grinding the surface of the spacer 4A6 and changing the thickness of the spacer 4A6, or by changing the spacer to an appropriate thickness. It is made to be substantially zero by exchanging it for a new one. Finally, by tightening the bolt 4A7, the adjusted height position of the tare 5A is maintained constant.

The connection between the screw rod 4A3 and the upper end of the tare 5A is performed by a spherical slide bearing 4A10, which is provided with a ball 4A11 provided at the lower end of the screw rod 4A3.
And a socket 4A12 provided at the upper end of the tare 5A for accommodating the ball.

The tare 5A is formed in an L shape and includes a vertical arm 5A1 connected to the suspension member 4A and a weighing object support arm 5A2 extending laterally from a lower end of the vertical arm. The tare 5A is connected to a fixed holding member 7A attached to the column 1A by a link mechanism 6A on the side opposite to the side on which the weighing object support arm 5A2 is provided.
The link mechanism 6A has levers 6A1 and 6A2 which are juxtaposed at an interval in the vertical direction. Both levers have one end bearing on the tare 5A and the other end bearing on the fixed holding member 7A. The bearing portions of the levers 6A1 and 6A2, that is, the fulcrums 6A3, 6A4, 6A5, and 6A6 are arranged so that a straight line connecting these fulcrums sequentially becomes a parallelogram, and preferably each interior angle of the quadrangle is 90 °. The fine angle adjustment is performed by the height adjusting device described above. The bearings of the above bearings are constituted by ball bearings.

The fixed holding member 7A is attached to the column 1A so as to be finely moved up and down.

As described above, the left and right tares 5A and 5B and their related members have the same configuration.
Regarding the tare 5B on the right side and members related thereto, the same members as those on the left side are denoted by reference numerals with B added thereto, and detailed description is omitted. However, in order to hold the weighing object W at a predetermined position, the weighing object support arm 5A2,
The configuration of the weighing object support portion provided in 5B2 is adapted to be compatible with weighing objects having different structures at both ends, such as a connecting rod of an engine.

In the embodiment shown in FIG. 1, the left tare 5A
The weighing object support arm 5A2 is configured to hold the large end W1 of the connecting rod, and the weighing object support arm 5B2 of the right tare 5B is configured to hold the small end W2 of the rod. The large end supporting portion 8A has a positioning pin 8A1 and support rollers 8A2 rotatably supported by ball bearings on both sides of the positioning pin. The positioning pin 8A1 and the support roller 8A2 are mounted on the support plate 8A3, and the support plate 8A3 can be adjusted on the upper surface of the weighing object support arm 5A2 via an adjustment plate 8A4 for height adjustment. It is supported to be. Similarly, the right small-end supporting portion 8B also has a positioning pin 8B1 and a supporting roller 8B2. The supporting roller 8B2 is supported by ball bearings on both sides of the positioning pin 8B. The positioning pin 8B1 and the supporting roller 8B2 The supporting plate is attached to the upper surface of the weighing object support arm via a height position adjusting plate 8B4 so as to be position-adjustable. The positioning pin 8B1 has a diameter dimension that can be loosely fitted into a bearing hole formed at the small end of the connecting rod. The left and right support rollers 8A2, 8B2 are arranged such that their axes are parallel to each other. When weighing another weighing object having different dimensions, the positioning pin 8A1,
In order to change the positions of 8B1 and the supporting rollers 8A2 and 8B2, the mounting positions of the supporting plates 8A3 and 8B3 can be shifted to be adjusted. However, other exclusive use having the positioning pins 8A1 and 8B1 and the supporting rollers 8A2 and 8B2 is possible. The adjustment may be performed by using a support plate and reattaching.

The above-mentioned weighing device operates as follows, for example, when weighing a connecting rod (hereinafter simply referred to as a connecting rod). Of the two positioning pins whose positions have been adjusted in accordance with the dimensions of the connecting rod W to be weighed, a bearing hole formed in the small end of the connecting rod is fitted to the right positioning pin 8B1, and the small end is placed on the support roller 8B2. At the same time or back and forth, fit the left positioning pin 8A1 into the bearing hole provided at the large end, and attach the large end to the support roller 8
The connecting rod is placed on A2, and the connecting rod is fixed in a state of being bridged between the two weighing object support arms 5A2 and 5B2. Even if a force due to a shift or the like acts between the connecting rod and the support rollers 8A2 and 8B2 during the work by the robot or the hand until reaching the steady state, the support roller rotates and absorbs the force. The force does not remain until after the steady state and does not affect the weighing result.

The connecting rod is connected to the left and right weighing object support arms 5A2,
Even if a force that laterally swings the tares 5A and 5B is generated by the movement of the center of gravity that occurs when the tare 5B2 is stationary, the force is received by any of the link mechanisms 6A or 6B, and the tare is virtually prevented from rolling. Is done. Vertical arm of tare 5A
1, 5B1, the large and small end weights of the connecting rods are not affected by the link mechanisms 6A, 6B having a low frictional structure, and the suspension members 4 having a low frictional structure are not affected.
All are transmitted to the weighing devices 3A and 3B via A and 4B and are accurately measured.

FIG. 2 shows another embodiment of the present invention. In this embodiment, a special cassette is used for each weighing object having a different size and shape so that the weighing of different weighing objects can be promptly performed. Has been made. In the figure, 9A indicates the cassette, and the cassette has a weighing object supporting arm 5A2,
Pin holes 9A1 and 9B1 are provided for fitting into cassette positioning pins 10A and 10B provided on the upper side of 5B2. This pin hole is formed at the same position in any cassette, and is commonly fitted to the cassette positioning pins 10A and 10B of one weighing device.

The cassette 9A has cassette supporting rollers 9A2 and 9B2 on both sides thereof. One pair of supporting rollers 9A2 rotates on the upper surface of the weighing object support arm 5A2, and the other pair of supporting rollers 9B2. It is designed to rotate on the upper surface of the weighing object support arm 5B2, so that an unfavorable frictional force remains between the cassette 9A and the two support arms 5A2, 5B2 in a steady state after the cassette is placed. Not to be done.

On the upper part of the cassette 9A, a large end pin 9A3 which fits in a bearing hole W1a of a work W, for example, a large end W1 of a connecting rod, and a small end pin 9A which engages in a bearing hole W2a of a small end W2. A pin 9B3 is provided, the axis of the large-end pin 9A3 is in a vertical plane passing through the axis of the pair of support rollers 9A2, and the axis of the small-end pin 9B3 is set to the pair of support rollers 9B.
In a vertical plane passing through two axes.

The small end pin 9B3 has a width smaller than that of the bearing hole W2a, but in the longitudinal direction, the width of the bearing hole W2a is small.
It is only slightly smaller than the diameter of 2a. Therefore, the small end after being inserted into the small end pin 9B3 is held at a specified position without lateral vibration.

As is apparent, the weight of the large end of the connecting rod is applied to the weighing support arm 5A2 via the pair of support rollers 9A2, and the weight of the small end is applied to the weighed object support arm 5B2 via the pair of support rollers 9B2. Therefore, each weight is accurately weighed by the weighing devices 3A and 3B via the tare having the special structure according to the present invention, as in the case of the embodiment of FIG.

[0026]

According to the present invention, as described above, two points of a weighed object can be accurately and quickly weighed, so that the present invention can also be used for mass production equipment where cycle time is a problem. In addition, since it is easy to change the distance between the two weighing positions, it is possible to weigh many types of weighing objects.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of a weighing device according to the present invention.

FIG. 2 is a front view showing another embodiment of the weighing device according to the present invention.

FIG. 3 is a front view schematically showing a conventional weighing device.

[Explanation of symbols]

 1A, 1B ... Support 2A, 2B ... Upper plate 3A, 3B ... Weighing meter 3A1, 3B1 ... Underfloor weighing hook 4A, 4B ... Hanging member 4A1 4A1, 4B2 ... screw rod 4A3, 4B3 ... screw rod 4A4, 4B4 ... upper flange plate 4A5, 4B5 ... lower flange plate 4A6, 4B6 ... spacer 4A7 , 4B7 ... fixing bolt 4A8, 4B8 ... lock nut 4A9, 4B9 ... lock nut 4A10, 4B10 ... spherical plain bearing 4A11, 4B11 ... ball 4A12, 4B12 ... socket 5A, 5B ····· Tare 5A1, 5B1 ··· Vertical arm 5A2, 5B2 ··· Weighing support arm 6A, 6B ···· Link mechanism 6A1, 6B1 ··· Lever 6A2, 6B2 ··· Lever 6A3, 6B3 ··· Support point (bearing part) 6A4, 6B4 ··· Support point (bearing part) 6A5, 6B5 ··· Support point (bearing part) 7A, 7B ··· · Fixed holding member 8A · · · · · Large end support 8B · · · · · Small end support 8A1, 8B1 · · · Positioning pins 8A2, 8B2 · · · Support roller 8A3 8B3 ··· Carrier plate 8A4, 8B4 ··· Height adjustment plate 9A ····· Cassette 9A1, 9B1 ··· Pin hole 9A2 and 9B2 ··· Cassette carrier roller 9A3 ··· ..Large end pin 9B3 ... Small end pin 10A, 10B ... Cassette positioning pin W ... Weighing object W1 ... Large end Part W1a ・ ・ ・ ・ ・ ・ Bearing hole W2 ・ ・ ・ ・ ・ ・ ・ Small end W2a ······· bearing hole

Claims (5)

[Claims] 1. A weighing hook of two weighing scales juxtaposed at a distance from each other, the weighing hook has two tare units suspended via suspending members, respectively, and each of the tare units is the above-mentioned suspended unit. A vertical arm connected to the member and hanging therefrom, and a weighing object supporting arm extending laterally from the vertical arm, and the weighing object supporting arms support the weighing object in a cross-linked state between the supporting arms; As described above, the two vertical arms and the hanging member are connected to each other by a connecting means having a small frictional force with respect to their mutual movement. Weighing device, characterized in that the vertical arms are each connected to a fixed holding member on the side thereof by a low-friction operating link mechanism which allows substantially only vertical movement of each vertical arm. 2. The connecting means for connecting the two vertical arms to the suspension member is a spherical plain bearing, and each link mechanism has two upper and lower levers for connecting between the tare vertical arm and the stationary holding member. The position of each fulcrum is determined such that a straight line connecting the fulcrum of each of the connecting portions is a parallelogram, and each fulcrum is constituted by a ball bearing. Weighing device. 3. The weighing material support arm of each tare has a positioning pin and a support roller provided at a weighing material support position, and both support rollers are arranged so that their axes are parallel to each other; The weighing device according to claim 1, wherein the weighing device is supported by a bearing. 4. A locating pin and a support roller are mounted on a support plate, and the support plate is mounted and fixed on a weighing object support arm via an adjustment plate for adjusting the height thereof. The weighing device according to claim 3. 5. It has a cassette for placing weighed materials,
The cassette includes a cassette supporting roller that movably supports the cassette on the upper surface of the weighing object support arm of both tares, and a pin hole that is fitted to a cassette positioning pin provided on each of the weighing object support arms. The weighing device according to claim 1, wherein the weighing device has a weighing device.