JP2505474Y2 - Load weight measuring device for cargo handling equipment - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a load weight measuring device for a cargo handling machine, which is mounted on a cargo handling machine such as a front loader for agricultural machinery or a forklift, and measures the loaded weight. is there.

[Conventional technology]

When carrying by a cargo handling machine such as a front loader, it may be necessary to measure the loaded weight. For example, when fertilizers, feeds, etc. are taken out from a storage place and mixed in a container, it is necessary to measure various fertilizers, etc., which are the components to be mixed. Further, when loading a truck or the like using a front loader, it is necessary to measure the weight before loading in order to keep the load limit of the truck.

In the case of performing such measurement, conventionally, a hanging scale such as a load cell is used, or a platform scale is used to perform measurement.

[Problems to be solved by the device]

However, the hanging scale requires transshipment work for measuring the weight, which takes time and effort. In addition, there is a problem in that a platform scale on which the tractor is mounted requires a large scale.

Therefore, in the front loader, a measuring device that calculates the loaded weight from the pressure of the cylinder that drives the lift arm up and down has been considered, but there is a problem that a practical measurement system cannot be obtained. That is, the load on the lift arm fluctuates greatly depending on the position of the center of gravity of the load placed on the bucket at the end of the lift arm, and accurate load measurement cannot be performed with cylinder pressure.

The purpose of the present invention is to provide a load weight measuring device for a cargo handling machine having a simple structure, which enables weight measurement while carrying out cargo handling work, improves the efficiency of the measurement work, and can measure without changing the position of the cargo. Is to provide.

[Means for solving the problem]

The load weight measuring device of the present invention comprises a parallel double beam and a strain gauge, and is interposed between the attachment mounting seat and the work attachment of the cargo handling machine.

The parallel double beam is a structure in which two elastic beams arranged vertically are fixedly joined to each other by a pair of rigid bodies, and a body mounting portion and an attachment coupling portion to be mounted on an attachment mounting seat and a work attachment are connected to the pair of rigid bodies. It is provided in each. The strain gauge is of a resistance change type or a semiconductor type and is attached to each elastic beam to form a bridging circuit. The main body attachment portion and the work attachment coupling portion are detachably attached to the attachment attachment seat and the attachment portion on the back surface of the work attachment, respectively. The attachment portion on the rear surface of the attachment is detachably attached to the attachment attachment seat for attaching the work attachment.

[Action]

The load weight measuring device is detachably attached between the attachment attachment seat and the work attachment of the cargo handling machine. When a load is placed on the work attachment in the attached state, the elastic beam of the parallel double beam is bent, and the strain gauge attached to the elastic beam is distorted. This distortion is detected as an electric signal by the bridge circuit, and the weight of the package is measured from the amount of distortion.

In this case, the parallel double beam is deformed so that the rigid body portion on the side of the work attachment is translated downward. Therefore, by appropriately configuring the bridge circuit, the moment applied to the elastic beam is not detected, but only the vertical force is detected. Therefore, even if the load is unevenly placed on the work attachment, the weight can be accurately measured.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS. 1 to 9.

In FIG. 3, the cargo handling machine 1 comprises a front loader, and an attachment mounting seat 3 is attached to the tip of the lift arm 2.
And a work attachment 5 which is detachably attached to the attachment attachment seat 3. A load weight measuring device 6 is attached between the attachment attachment seat 3 and the work attachment 5.

The lift arm 2 is attached to a base metal 8 fixed to the tractor 7 so as to be vertically rotatable, and is lifted and lowered by a lift cylinder 9. The attachment mounting seat 3 is mounted on the lift arm 2 so as to be rotatable up and down around a support shaft 10, and is connected to an angle adjusting cylinder 13 via a link 11 and a rotating lever 12. The attachment mounting seat 3 has a hook 3a on the upper end.
And the connection hole 3b is provided at the lower end.
Two lift arms 2 are provided in parallel to each other on the left and right of the tractor 7, and both lift arms 2 are joined to each other in the longitudinal direction by horizontal crosspieces (not shown). Two attachment mounting seats 3 are also provided in parallel, and are integrally joined to each other by horizontal crosspieces. The two attachment mounting seats 3 do not necessarily have to be joined by a horizontal rail.

The work attachment 5 comprises a bucket as shown in FIG. 4, and a pair of mounting portions 14 are provided on the back surface.
Each mounting portion 14 is provided with an engaging pin 15 between the upper portions of two parallel vertical plates 14a and a connecting hole 16 in the lower portion of each vertical plate 14a. When the loaded weight measuring device 6 is not used, the attachment mounting seat 3 is inserted between the two vertical plates 14a of each mounting portion 14, and the hook 3a thereof is engaged with the engagement pin 15. Further, a connecting pin or a bolt is inserted across the connecting hole 16 of the connecting plate 14a and the connecting hole 3b of the attachment mounting seat 3. As a result, the work attachment 5 is attached to the lift arm 2.

As shown in FIG. 5, the loaded weight measuring device 6 includes a pair of rigid bodies 18 and 19 at both ends of two elastic beams 17 arranged vertically.
And a parallel double beam 20 fixedly joined to each other, and four strain gauges A to D attached to the inner surfaces of both ends of both elastic beams 17, respectively. On one rigid body 18, a hook 21a is provided at the upper end and a connecting cylinder 21b is provided so as to project from both surfaces of the lower end, and the hook 21a and the connecting cylinder 21b constitute an attachment coupling portion 21. The other rigid body 19 is formed in a groove shape as shown in FIG. 7, and an engaging pin 22a is provided between both flange portions at the upper end, and a connecting hole 22b is provided at both flange portions at the lower end. The engaging pin 22a and the connecting hole 22b form a main body attaching portion 22. An inclination sensor (not shown) is attached to the side surface of the rigid body 19 via a sensor attachment member 23. The space between the rigid bodies 18 and 19 is preferably covered with a cover (not shown) to protect the strain gauges A to D.

Two load weight measuring devices 6 are attached to the attachment portion 14 of the work attachment 5 of FIG. 4 and are connected to the attachment attachment seats 3 of the two lift arms 2.
In this case, the hook 21a of the loaded weight measuring device 6 is engaged with the engagement pin 15 in the mounting portion 14 of the work attachment 5. The connecting cylinder 21b is inserted between the two vertical plates 14a, and a connecting pin or bolt is inserted between the connecting cylinder 21b and the connecting hole 16. The attachment mounting seat 3 is inserted into the groove portion of the rigid body 19 of the load weight measuring device 6, and the hook 3a is engaged with the engaging pin.
22a is engaged. The connecting hole 3b is aligned with the connecting hole 22b, and a pin or a bolt is inserted therethrough.

FIG. 9 is an electric circuit diagram. In each of the left and right load weight measuring devices 6, the four strain gauges A to D and A'to D'constitute a bridge circuit, and the left and right bridging circuits correspond to the corresponding strain gauges A to D, A '. .About.D 'are respectively connected in parallel. In the figure, ± EXC is a voltage application terminal and ± SIG is an output terminal. By applying a constant voltage between the terminals + EXC, -EXC, the resistance value change of each strain gauge A to D, A'to D ' , The voltage value between terminals + SIG and -SIG is detected. The detected voltage is converted into a weight value by the processing circuit and displayed on a digital display means or the like provided on the display panel.
The display panel is arranged on the driver's seat of the tractor 7. The processing circuit is provided with a zero adjustment key and the like for displaying the net weight.

Next, the usage method and the like will be described. As shown in FIG. 3, the loaded weight measuring device 6 firstly includes the work attachment 5
Attach it to the attachment mounting seat 3 by scooping with the lift arm 2. After attachment, work attachment 5
The zero adjustment key is set to zero so that the weight of is canceled.

When the preparation is completed in this way, the load is placed on the work attachment 5 and the angles of the lift arm 2 and the attachment mounting seat 3 are adjusted so that the rigid bodies 18, 19 of the parallel double beam 20 are vertical. Read the measured value in this state.

The measured value is obtained as follows. That is, when a load is placed on the work attachment 5, the elastic beam 17 of the parallel double beam 20 is bent, and the strain gauges A to D (A 'to D') attached to the elastic beam 17 are distorted. This distortion is detected as a voltage signal by the bridge circuit, converted into a weight value by the processing circuit, and displayed.

In this case, the parallel double beam 20 can be considered as a model as shown in FIG. 8, and the rigid body 18 on the work attachment 5 side can be considered.
Deforms so that it translates downward. Further, strain gauges A to D (A 'to
D ') is configured as a bridge circuit that takes the average of each distortion. Therefore, the moment applied to the elastic beam 17 is not detected, but only the vertical force is detected. Therefore, even if the luggage is unevenly placed on the work attachment 5 forward and backward, the weight can be accurately measured. With respect to the left and right deviation of the load, the strain gauges A to D and A'to D'of the left and right load weight measuring devices 6 are connected in parallel to obtain the average value of the resistance change. Can be measured accurately regardless of The left and right load weight measuring devices 6 are configured independently, but the work attachment 5
Is considered to be a rigid body, and the left and right attachment mounting seats 3 are also considered to be one rigid body fixed to each other. Therefore, by taking out the average value as described above, it is possible to cope with the lateral deviation of the luggage. The left and right load weight measuring devices 6 in this embodiment may be integrated into one load weight measuring device.

The posture of the load weight measuring device 6 needs to be kept vertical because the accuracy decreases when it is greatly inclined, but it is displayed by the inclination sensor or the like that it is in an angle range (for example, ± 5 °) in which normal measurement can be performed. By doing so, the posture can be easily adjusted.
A level or a plumb bob may be used as the angle sensor.

The loading weight measuring device 6 is thus constructed as described above.
Since it is configured to be mounted on the attachment mounting seat 3 to measure the loaded weight of the work attachment 5, the weight can be measured while performing the cargo handling work. In addition, even if the load is unevenly placed on the work attachment 5, the measurement can be accurately performed. Therefore, the weight measurement can be efficiently performed in various applications, and the convenience of use of the cargo handling machine 1 and the expansion of the applications can be achieved.

For example, since (a) fertilizer, feed, etc. can be transported while measuring the weight, they can be mixed simply by putting several kinds of fertilizer etc. in a container. (B) Since the loaded weight can be grasped, safe transportation that does not exceed the limit can be performed, and it is possible to prevent the luggage from being dropped off on the way. (C) The weight loaded on a truck or the like can be measured, and the limit load can be protected. (D) The roll weight can be achieved when the roll wound with grass is transported, and the dryness can be known from this weight. (E) Since the weight of a bag or the like is known during transportation, the weight can be easily confirmed during the distribution process.

10 and 11 show another embodiment. In this example, the hook 21c forming the attachment coupling portion 21 is opened upward.

In the case of such a construction, as shown in FIG. 11, after mounting the loaded weight measuring device 6 on the attachment mounting seat 3 of the lift arm 2, the work attachment 5 is scooped by the loaded weight measuring device 6 to perform the work. Attachment 5 can be attached. Other configuration effects are the same as those of the above-described embodiment.

FIG. 12 shows still another embodiment. In this example, the attachment coupling portion 24 is configured by a separate member from the rigid body 18 of the parallel double beam 20, and the angle can be adjusted around the pin 25. The attachment joint portion 24 and the rigid body 18 can be fixed at an arbitrary angle by a link 26 joined by a long hole 27. When the angle is adjustable in this way, the object of measurement is widened.

13 to 15 show still another embodiment.
In each of these embodiments, the parallel double beam 30 is
A pair of elastic beams 17 are formed by forming a sheet of metal plate and providing openings 31 to 33, respectively. Other structural effects are similar to those of the embodiment shown in FIG.

In each of the above-mentioned embodiments, the case where the cargo handling machine 1 is a front loader for agricultural machinery has been described. However, in a forklift, between the attachment mounting seat formed of the elevating frame provided on the mast and the work attachment such as a fork. The load weight measuring device of the present invention can be applied to the case where the device is attached to the same.

Further, the loaded weight measuring device 6 in each of the above-mentioned embodiments is
It is not always necessary to use two as a pair, and only one may be used alone.

Furthermore, the strain gauges A to D, A'in each of the above embodiments
Semiconductor strain gauges may be used for D '.

[Effect of device]

Since the load weight measuring device of the cargo handling machine of the present invention is configured to be mounted between the attachment mounting seat and the work attachment of the cargo handling machine, the load weight can be measured while performing the cargo handling work, and the measurement work can be performed efficiently. You can do it well. Moreover, it can be easily attached to and detached from the cargo handling machine, and the structure is simple. Further, since it is composed of the parallel double beam and the strain gauge, there is an effect that even if the load is unevenly placed on the work attachment, the measurement can be accurately performed and the weight measurement can be performed more easily.

[Brief description of drawings]

FIG. 1 is a side view showing the relationship between a load weight measuring device and a cargo handling machine according to an embodiment of the present invention, FIG. 2 is a side view of the disassembled state, and FIG. 3 is an explanatory view of its mounting operation. FIG. 4 is a perspective view of a work attachment of the cargo handling machine, FIGS. 5 to 7 are side views, a rear view and a plan view of the loaded weight measuring device, respectively. FIG. FIG. 9 is an explanatory view of the principle of the measuring device, FIG. 9 is an electric circuit diagram of the same, FIG. 10 is a side view of another embodiment, FIG. 11 is an explanatory view of its operation, and FIGS. It is a side view of an Example. 1 ... cargo handling machine, 2 ... lift arm, 3 ... attachment mounting seat, 4 ... work machine body, 5 ... work attachment, 6 ... loaded weight measuring device, 7 ... tractor,
17 …… Elastic beam, 18,19 …… Rigid body, 20 …… Parallel double beam, 21 …… Attachment joint part, 22 …… Main body mounting part, 30 …… Parallel double beam, A to D, A ′ to D ′ ...... Strain gauge

Claims (1)

(57) [Scope of utility model registration request] 1. A cargo handling system comprising: a work machine main body that drives an attachment mounting seat up and down; and a work attachment that has a mounting portion on a back surface and is detachably mounted on the attachment mounting seat by the mounting portion to perform a cargo handling work. A load weight measuring device to be mounted on a working machine, wherein a parallel double beam in which two ends of two elastic beams arranged vertically are fixedly joined to each other by a pair of rigid bodies, and a bridge circuit attached to each elastic beam And a plurality of strain gauges constituting the above, and a cargo work machine provided with the pair of rigid bodies, and a main body mounting portion and a working attachment coupling portion that are detachably attached to the attachment mounting seat and the mounting portion of the work attachment, respectively. Load weight measuring device.