JPS6318885Y2 - - Google Patents

Description

[Detailed description of the invention] Technical field This invention relates to a clamping device installed on a forklift or the like, and more specifically, a pair of opposing clamp pads accurately measure the diameter of a rolled material to be clamped, such as rolled paper. This invention relates to a clamp device.

Conventionally, in a roll clamp device that clamps a roll-shaped cargo, when measuring the diameter of the roll-shaped cargo to be clamped, it is measured directly with a tape measure, or by measuring the diameter of the roll-shaped cargo to be clamped. A slide rail 5 reciprocates along the guide member 3 based on the operation of the clamp cylinder 2 of the clamp device 1 and relatively rotates the clamp arm 4.
A pointer 6 is provided on the guide member 3, and a scale plate 7 is provided on the guide member 3 so as to correspond to the pointer 6. By reading the scale on the scale plate 7 indicated by the pointer 6, the amount of rotation of the clamp arm 4, that is, the amount of rotation of the clamp arm 4 can be determined. There was one that measured the diameter of a cargo 11 clamped between the pad 8 of the clamp arm 4 and the pad 10 of the support arm 9.

However, in the former case, although the diameter of the cargo 11 can be accurately measured, the efficiency of cargo handling work is very poor. In the latter case, although the work efficiency is improved, the diameter of the cargo 11 cannot be measured accurately. That is, when both pads 8 and 10 clamp a wide range of cargo objects 11 ranging from large diameters to small diameters, when clamping each cargo object 11 opposite to the diameter of each cargo object 11, both pads 8 and 10
When the contact surface position of the clamp arm 4 with respect to the cargo object 11 is always uniquely determined at a predetermined position, the amount of rotation of the clamp arm 4 is determined relative to the diameter of the cargo object 11. Can be measured accurately.

However, in reality, the position of the contact surface of the pads 8, 10 with respect to the cargo object 11 is not uniquely determined depending on the diameter of the cargo object 11, and especially in the case of a cargo object 11 with a small diameter, as shown in FIG. As shown in FIG.
is often clamped.

Therefore, as described above, it is not possible to accurately and reliably measure the diameter of the cargo object 11 only by the amount of movement of the slide rail 5, that is, the amount of rotation of the clamp arm 4.

Purpose The purpose of this invention is to solve the above-mentioned problems and provide a clamping device for forklifts, etc., which can accurately and reliably measure the diameter of cargo to be handled, and which can improve cargo handling efficiency. be.

Embodiment Hereinafter, an embodiment of a forklift clamp device embodying this invention will be described with reference to the drawings.

In FIG. 4, the support arm 21 is attached to the mast (not shown) of a forklift so that it can be raised, lowered, and rotated via an elevating device (not shown) and a rotating device (not shown). A clamp pad 22 is supported by a connecting pin 23 at the portion. First and second pressure sensors 24 and 25 are disposed at the outer and inner ends of the clamp surface 22a of the clamp pad 22, respectively. The first and second pressure sensors 24 and 25 are pressure sensing members such as semiconductor pressure sensing elements, strain cages, pressure sensitive resistors, or conductive rubber. In this state, by being pressed by the cargo handling object 26, detection signals SG1 and SG2 are output to an electric control circuit to be described later.

The clamp arm 27 is rotatably supported by the support arm 21 via a rotation shaft 28 fixed to its base end, and a clamp pad 29 is supported by a connecting pin 30 at its distal end. The outer end of the clamp surface 29a of the clamp pad 29,
Third to fifth pressure sensors 31, 32, and 33 are arranged at the center and inner end positions. The third to fifth pressure sensors 31, 32, 33 are the same pressure detection members as the first and second pressure sensors 24, 25, and detect when pressed by the cargo 26, respectively. Signal SG3, SG4,
Output SG5 to an electric control circuit to be described later. The third to fifth pressure sensors 31, . . . , 33 together with the first and second pressure sensors 24, 25 constitute a clamp state detection device, and detection signals SG1, . Together, these are used as clamp data for detecting the clamping state of the load object 26, that is, the clamp position of the load object 26 on the clamp surfaces 22a, 29a of the clamp pads 22, 29.

The clamp cylinder 34 has its base end rotatably supported by a support shaft 35 relative to the base end of the support arm 21, and the tip of its piston rod 36 is attached to an intermediate position of the clamp arm 27. It is rotatably supported by a support shaft 37. When the clamp cylinder 34 operates, the clamp arm 27 is rotated about the rotation shaft 28.

As shown in FIG. 5, the rotation angle detection device 38 is fixed to the support arm 21 so that a gear 40 fixed to the tip of the driven shaft 39 meshes with a gear 41 fixed to the rotation shaft 28, Based on the rotation of the rotation shaft 28, an encoder (not shown) fixed to the base end of the driven shaft 39 is rotated, thereby converting the rotation angle of the clamp arm 27 into a digital amount. It is output as dynamic data to the electric control circuit described later.

Next, the electric control circuit of the clamping device constructed as described above will be explained with reference to FIG.

In FIG. 6, a central processing unit (hereinafter referred to as CPU) 42 is a read-only storage device that stores program data, conversion and correction data for determining the diameter of the roll-shaped cargo 26, and various other data. (hereinafter referred to as ROM) 43
The first to fifth pressure sensors 2 constitute an arithmetic and control unit, and are built in a control box (not shown) in the driver's seat of the forklift.
Detection signals SG1, from 4, 25, 31, -, 33
~, SG5 (clamp data) and rotation data output from the rotation angle detection device 38 are input. The conversion data stored in the ROM 43 converts the rotation data of the rotation angle detection device 38 into the case where the cargo object 26 is clamped by the ideal clamp surfaces 22a and 29a where the clamp pads 22 and 29 are uniquely determined. This is data for converting into the diameter of the cargo handling object 26 at the assumed time, and is based on the rotation angle of the clamp arm 27 and the clamp surfaces 22a, 2.
Since the relative relationship with the diameter of the load 26 clamped at the position 9a is generally not linear, the relative relationship is determined in advance and used as conversion data. In this embodiment, the rotation range of the clamp arm 27 is set to 0°~
90° (0° is when the clamp arm 27 is maximally expanded relative to the support arm 21, and 90° is when it is minimally closed), and the diameter of the cargo 26 to be clamped at that time. is diameter 1300mm ~ diameter 250
mm, the clamp arm 27 is more than 0° between
The diameter of the cargo object 2 when it rotates up to 90 degrees in 1 degree increments is determined in advance by drawing or calculation and is stored in the ROM 43 as conversion data.

Therefore, the CPU 42 detects the rotation angle detection device 38.
Rotation data is input from the ROM 43, conversion data corresponding to this rotation data is read from the ROM 43,
The diameter of the cargo 26 at that time is calculated.

Further, the correction data stored in the ROM 43 allows the diameter of the cargo object 26 calculated based on the conversion data to be very close to the true diameter when the cargo object 26 is not in the ideal clamped state. data for correcting the detection signal to a value
Based on the clamp data of SG1 to SG5, correction values for each clamp state of the cargo object 26 are determined in advance by drawing or calculation, and are used as correction data.

Therefore, the CPU 42 receives the detection signals SG1, . . . , SG.
Based on the clamp data consisting of 5, the clamp state of the clamped cargo 26 is determined, and correction data corresponding to the clamp data is stored in the ROM.
43 and the diameter of the cargo object 26 calculated based on the conversion data is corrected to the actual diameter of the cargo object 26 based on the correction data.

The display drive circuit 44 is a display section provided at a predetermined location on the driver's seat of the forklift, which displays the value of the diameter of the cargo 26 calculated based on the conversion and correction data in response to the control signal output from the CPU 42. 45. The print drive circuit 46 similarly stores the calculated value of the diameter of the cargo object 26 in a printer 47 installed at a predetermined location in the driver's seat in response to a control signal output from the CPU 42. A print command switch 48 is provided on the operation panel (not shown) of the control box, and when pressed, a print signal is sent to the CPU.
42. and
The CPU 42 outputs the control signal to the print drive circuit 46 only when this print signal is input.

Next, to explain the operation of the clamping device configured as above, when a cargo object 26 with a large diameter is being clamped as shown in FIG.
The rotation angle of the clamp arm 27 at that time is
The CPU 42 detects the rotation data based on the rotation data of the rotation angle detection device 38, reads the conversion data corresponding to the content from the ROM 43, and calculates the diameter D of the cargo object 26 in an ideal clamping state at the rotation angle.
Calculate 1. Next, the CPU 42 corrects the diameter D1 based on the difference in the clamping state of the cargo 26. Then, as shown in FIG. 4, the cargo 26
is the clamp surface 22 of the clamp pads 22, 29
a, 29a, and each pressure sensor 24, 2
5, 31, 32, 33 are pressed, CPU4
2 is input with clamp data of H level detection signals SG1, . . . , SG5. At this time, CPU42
Since the detection signals SG1, -, SG5, which are all at H level, are input, it is determined that the cargo 26 is in an ideal clamping state that is uniquely determined by the rotation angle, and the processing is performed without reading out the correction data. , the diameter D1 calculated based on the conversion data
is calculated as the actual diameter of the load 26 currently being clamped, and the diameter D1 is displayed on the display section 45.
to be displayed digitally. At this time, when the operator operates the print command switch 48, the CPU 42 causes the printer 47 to record the diameter in response.

Next, when a cargo object 26 with a small diameter is being clamped as shown by the solid line in FIG. The corresponding conversion data is read from the ROM 43, and the diameter D2 of the cargo object 26 in an ideal clamping state at that amount of rotation is calculated.

At this time, as shown in FIG. 7, only the fourth pressure sensor 32 is pressed by the cargo object 26, and the CPU
42 has L level detection signals SG1, ~, SG3,
The clamping data of SG5 and H level detection signal SG4 are input, and the CPU 42 determines that the cargo object 26 is in an ideal clamping state that is uniquely determined by its rotation angle based on this data. Without reading out the correction data, the diameter D2 calculated based on the conversion data is processed as the actual diameter of the cargo object 26 currently being clamped. Then, the CPU 42 causes the display unit 45 to digitally display the diameter D2 in the same manner as described above, and causes the printer 47 to store the diameter D2.

Next, the cargo object 26 having a diameter D3 smaller than the diameter D2 is not clamped in the uniquely determined ideal clamp state, and as shown by the dashed line in FIG. When the load object 26 is clamped in a typical clamp state, the CPU 42 first calculates the rotation angle at that time, that is, the diameter D2 of the load object 26 described above, based on the conversion data as described above. At this time, two of the first and third pressure sensors 24 and 31 are pressed by the load 26 with a diameter D3, and the CPU 42 provides clamp data of L level detection signals SG2, SG4, SG5 and H level detection signals SG1 and SG3. is input, and based on this data, the CPU 42 determines that the clamped object 26 is not in an ideal clamping state that is uniquely determined by the amount of rotation of the clamp arm 27, and that the object 26 has a diameter of D2. It is determined that a smaller cargo object 26 is being clamped.

Next, the CPU 42 reads out the correction data [ΔD] corresponding to this piston rod, executes a calculation to subtract the diameter D2 calculated above by the correction data [ΔD], since the load object 26 is smaller than the diameter D2, and now clamps the piston rod. The actual diameter D3 (=D2 - ΔD) of the loaded object 26 is calculated. Then, the CPU 42 causes the display unit 45 to digitally display this diameter D3 in the same manner as described above, and causes the printer 47 to store it.

As described above, in this embodiment, the diameter of each cargo object 26 that is clamped in the ideal clamping state that is uniquely determined at the time corresponding to the preset rotation angle of the clamp arm 27 is used as conversion data.
It is stored in the ROM 43 and the rotation angle detection device 3
8 to detect the amount of rotation of the clamp arm 27 and read out the conversion data based on the rotation angle, the diameter of each cargo object 26 can be calculated. The clamping state of the cargo object 26 is detected by the first to fifth pressure sensors 24, 25, 31, -, 33 provided at 22a, 29a, and a preset correction value for each clamping state is determined according to the clamping state. (correction data) is read from the ROM 43 and the diameter of the cargo object 26 calculated based on the conversion data is corrected. Accurate and reliable measurements can be made, and cargo handling efficiency can be improved.

Note that this invention is not limited to the above-mentioned embodiments, but can also be implemented in the following manner.

○B In the above embodiment, two pressure sensors 24 and 25 are installed on the clamp surface 22a, and the two pressure sensors 24 and 25 are installed on the clamp surface 29a.
is equipped with three pressure sensors 31, 32, and 33, and the detection signal SG output from each sensor is
Although the clamp state is determined based on the state of SG5 and the correction data at that time is read out, the number of pressure sensors provided on each clamp surface 22a, 29a is further increased to obtain a more accurate clamp state. To determine this, increase the number of correction data accordingly, and read out more accurate data from the data.

○B In the above embodiment, a single-opening clamp device was explained, but the present invention can be applied to a double-opening type clamp device. In this case, a rotation angle detection device is provided on the two rotating clamp arms, and conversion data for these two rotation data is also calculated in advance by drawing or calculation (for example, X-Y distribution) and stored in the storage device. By doing so, the same effect as in the above embodiment can be obtained.

C. Instead of the pressure sensor, a contact sensor such as a micro switch, a proximity switch, etc. may be used to detect the presence or absence of contact with the cargo object 26.

○D The rotation angle detection device 38 is a potentiometer,
The rotation angle of the clamp arm 27 may be determined by detecting the rotation angle of the clamp arm 27 using a variable resistor, a magnetic resistance element displacement sensor, or the like, or by detecting the movement of the clamp cylinder 34.

Effects As detailed above, this device detects the rotation angle of the clamp arm and the clamp position on the clamp surface of the clamp pad of the cargo object, and converts the predetermined conversion data and correction data based on this detected data. Since the diameter of the cargo actually clamped on the clamp pad is calculated by reading the Since there is no need to measure the weight, it is effective in improving the efficiency of cargo handling operations, and is an excellent practical idea as a clamping device for forklifts, etc.

[Brief explanation of drawings]

Figure 1 is a perspective view of a clamping device in a conventional forklift, etc., Figure 2 is a side view, and Figure 3 is a side view.
The figure is an explanatory diagram showing the clamping state of the cargo to be handled by the clamp pad, Figure 4 is a side view of the clamp device for a forklift etc. that embodies this invention, and Figure 5
The figure is a partially cutaway side view showing the installation state of the rotation angle detection device, Figure 6 is the electric circuit diagram of the clamp device, and Figure 7 is the same clamp showing the state in which a cargo with a small diameter is being clamped. FIG. 2 is a side view of the device. Support arm...21, clamp pad...2
2, 29, Clamp surface...22a, 29a, First pressure sensor...24, Second pressure sensor...2
5. Cargo cargo...26. Clamp arm...27.
Rotation axis...28, third to fifth pressure sensors...
31, 32, 33, clamp cylinder...34,
Rotation angle detection device...38, central processing unit...4
2. Storage device...43, Display unit...45, Printer...47.

Claims (1)

[Scope of Claim for Utility Model Registration] 1 At least one of a pair of opposing clamp pads is attached to a rotatable clamp arm, and the clamp arm is rotated toward the other clamp pad by an arm operating mechanism such as a clamp cylinder. In a clamping device for a forklift or the like that clamps a roll-shaped cargo between both clamp pads by moving the clamp pad, the clamping device is provided on the rotation shaft of the clamp arm or the arm operation mechanism, and detects the rotation angle of the clamp arm. a rotation angle detection device; at least one clamp state detection device provided on a clamping surface of at least one of the pair of crank pads to detect a clamping position of the cargo on the clamping surface; and the rotation. Preset conversion data for determining the diameter of the cargo object at the clamp position on the ideal clamp surface that is uniquely determined with respect to the corner, and the conversion data for the clamp position on the clamp surface of the cargo object. a storage device that stores preset correction data for correcting the diameter of the cargo to be determined based on the diameter of the cargo to the actual diameter of the cargo; The rotation angle of the cargo is determined, and the predetermined conversion data for the rotation angle and the detection data from the clamp state detection device are input, the clamp position of the cargo on the clamp surface is determined, and the an arithmetic processing device that reads predetermined correction data from the storage device and calculates the actual diameter of the cargo clamped between the clamp pads based on both data; clamping device. 2. The fork according to claim 1 of the utility model registration, wherein the rotation angle detection device is an encoder that rotates with the rotation of the rotation axis of the clamp arm and detects the rotation angle of the rotation axis. Clamping device for lifts, etc. 3. The clamping device for a forklift or the like according to claim 1, wherein the clamping state detection device is a pressure sensor, and a plurality of pressure sensors are provided on the clamping surfaces of a pair of clamp pads.