JP3150617B2 - Rolling angle load test method and test device for forklift - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for safely and promptly performing a roll angle (rollover angle) load test, which is a stability test in a longitudinal direction (front-back direction) or a lateral direction (left-right direction) of a forklift. More specifically, the present invention relates to a test method and a test apparatus for determining a limit slope at which a vehicle does not fall when the vehicle is tilted forward or sideways.

[0002]

2. Description of the Related Art Conventional forklift rolling angle load test,
For example, as a turning angle load test in the vehicle front-rear direction, FIG.
As shown in FIG. 7, when the vehicle 102 loaded with the weights 101 is stopped on the tilting platform 103, the fork 105 is set to the maximum lift, and when the tilting platform 103 is gradually tilted, the rear wheel 104 The so-called weight loading method in which the angle of the tilt angle table 103 at the moment of lifting is visually observed is dominant. The above test is carried out two to three times while changing the weight.

[0003]

In the test of the weight loading method as described above, the weight 102 having the rated load is loaded and the vehicle 102 is tilted with the maximum lift, which is not always preferable in terms of safety measures. Since the test cannot be performed at the inclination angle of the standard, there is no other method than finally calculating the load load for the standard angle by calculation, and there is a limit in improving the accuracy of the load value for the standard angle.

On the other hand, it is possible to apply the load by, for example, a hydraulic actuator or the like, but in this case, a line connecting the load generating point on the actuator side and the load application point on the fork side is always maintained in a vertical state. It is difficult to improve the accuracy of the load value with respect to the standard angle similarly to the above.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a safe, quick and accurate test transmission or a turning angle load test apparatus.

[0006]

According to a first aspect of the present invention, there is provided a test method, wherein a forklift to be tested is stationary on an inclined table, and a fork of the forklift is lowered by a load generating means. The test load is gradually increased while applying a predetermined test load by towing, and the line connecting the load application point on the fork side and the load generation point on the load generation means side when the test load is applied is always vertical. And the test load at the moment when the rear wheel of the forklift lifts with the increase of the test load is detected as a turning load.

According to a second aspect of the present invention, in a state in which a forklift to be tested is stationary on an inclined table, the fork of the forklift is pulled downward by a load generating means to perform a predetermined test. A turning load test of a forklift in which the test load is gradually increased while applying a load, and the test load at the moment when the rear wheel of the forklift lifts up with the increase of the test load is detected as a turning load. In the apparatus, at least the load generating point on the load generating means side is such that a line connecting the load applying point on the fork side and the load generating point on the load generating means side when the test load is applied is always in a vertical state. It is characterized by having a degree of freedom of movement in a horizontal plane.

According to a third aspect of the present invention, the load generating means in the second aspect of the present invention is configured such that the tip of a horizontal articulated arm driven up and down by an actuator functions as a load generating point, or A direct-acting actuator is provided at the tip of the articulated arm, and the tip of the output rod of the actuator functions as a load generating point.

According to a fourth aspect of the present invention, in addition to the features of the third aspect of the present invention, a cable connecting a load application point on a fork side and a load generation point on a load generating means side, And a load sensor for detecting a test load applied to the strip.

According to a fifth aspect of the present invention, in addition to the features of the fourth aspect, a lift detecting means for detecting a moment of lifting of a rear wheel of a forklift to be tested, the lift detecting means, And a measurement signal processing means to which the output of the load sensor is input and holds and stores the indicated value of the load sensor at the moment when the rear wheel is lifted.

According to a sixth aspect of the present invention, in addition to the features of the fifth aspect, the fork is provided with a towing attachment for a rolling load test, and a part of the towing attachment is provided on the fork side. It is characterized by functioning as a load application point.

According to a seventh aspect of the present invention, in addition to the features of the sixth aspect, the tilt angle of the tilt angle table can be arbitrarily adjusted.

Therefore, in the inventions according to the first and second aspects of the present invention, the line connecting the load application point on the fork side and the load generation point on the load generation unit side is always kept vertical, Is gradually increased, and the load value at the moment when the rear wheel lifts up is detected as a turning angle load with respect to the inclination angle of the vehicle.

Then, as in the invention according to claim 3,
Since the load generation means is configured around a horizontal articulated arm, the line connecting the load application point on the fork side and the load generation point on the load generation means side faithfully follows the change in the tilt of the forklift. However, the vertical state of the line segment can be more accurately maintained.

According to a fourth aspect of the present invention, there is provided a cable connecting the load application point and the load generating point, and a sensor for detecting a load applied to the cable. Thus, the load applied to the fork is accurately detected by the load sensor as the tensile load of the cord, and furthermore, the lift detection means for the rear wheel, and the output and load of the lift detection means as in the invention according to claim 4. By having the measurement signal processing means which receives the output of the sensor and the input,
The test load value at the moment when the wheel lifts up is accurately held.

[0016]

According to the first and second aspects of the present invention, when a test load is applied by the load generating means, regardless of the change in the inclination of the forklift due to the load, the load application point on the fork side and the load generating means. Since the line connecting the load generation point on the side is always in a vertical state and the same test load as when a weight is loaded can be applied, the test can be performed in comparison with the case where the weight is actually loaded. Of course, it is possible to perform the test at a standard angle because it can be performed more safely, and it is possible to directly detect the load at that standard angle and obtain highly accurate correlation data between the inclination angle and the load. Being able to
The reliability of the data is greatly improved.

According to the invention of claim 3, according to claim 2,
Since the load generating means according to the invention described in (1) is configured around a horizontal articulated arm, the line connecting the load applying point on the fork side and the load generating point on the load generating means side is always in a vertical state. This can be made to faithfully follow the change in the attitude of the vehicle while maintaining such a value. In addition to the same effect as the invention described in claim 2, there is an advantage that the test accuracy is further improved.

According to the fourth aspect of the invention, the load application point on the fork side and the load generation point on the load generating means side are connected by a cord, and the tensile force applied to the cord is reduced. Since the test load is detected by the load sensor, there is an effect that the load applied to the fork can be more accurately detected in addition to the same effect as the invention described in claim 3.

According to the fifth aspect of the present invention, in addition to the above-mentioned cable body and the load sensor, a lift detecting means for detecting a moment when the rear wheel of the forklift lifts, and an output of the lift detecting means for receiving the output of the lift detecting means. The provision of the measurement signal processing means for holding and storing the load sensor indication value at the moment of the lifting, in addition to the same effect as the invention according to claim 4, as compared with the conventional one by visual recording This has the effect that the load value at the moment of lifting can be detected more accurately.

According to the sixth aspect of the present invention, the fork is provided with a traction attachment for a turning load test, and a part of the attachment functions as a load application point on the fork side. In addition to the effect similar to that of the invention described in Item 5, there is an effect that workability in setting up a test can be improved as compared with the case where the cord is directly connected to the fork.

According to the seventh aspect of the present invention, the inclination angle of the inclination angle table is configured to be arbitrarily adjustable.
In addition to the same effects as the invention according to claim 6, there is an effect that even when the inclination angle is changed, the operation can be performed quickly, and the versatility of the equipment is improved.

[0022]

2 and 3 are views showing a typical embodiment of a turning angle test apparatus according to the present invention. FIG. 2 is an explanatory plan view thereof, and FIG. 3 is an explanatory front view of FIG. FIG.

As shown in FIGS. 2 and 3, the turning angle test apparatus according to the present embodiment is roughly divided into a tilt which is provided on a floor 1 and can be arbitrarily tilted and displaced about a horizontal hinge pin 3 of a hinge 2 as a center of rotation. A square base 4, a first load generating device 5, which is erected on the floor 1 on the hinge 2 side of the tilt base 4, for a longitudinal turning load test, and the tilt base 4. It comprises second and third load generating devices 6 and 7 for lateral turning load test in the left-right direction facing each other on both sides.

The tilt angle table 4 is mounted with a forklift (hereinafter, referred to as a vehicle) T to be tested, and is operated in accordance with expansion and contraction of a lift cylinder (hydraulic cylinder) 9 installed in the pit 8. The tilting displacement is performed about the hinge pin 3 as a center of rotation.

FIG. 4 shows the details of the first load generating device 5. The first load generating device 5 is a horizontal multi-unit that moves up and down using a vertically moving cylinder (hydraulic cylinder) 10 as a drive source. It is configured around an articulated arm 11.

More specifically, a vertical post 12 is erected on the floor 1, and a cylinder tube 13 of an elevating cylinder 10 is externally inserted into the post 12. Thereby, the inside of the cylinder tube 13 is defined by two upper and lower pressure chambers 15 and 16. As shown in FIG. 2, the post 12 is supported by three inclined support rods 17 for preventing falling. Therefore, the lifting cylinder 1
In the case of 0, the cylinder tube 13 moves up and down along the post 12 by controlling the hydraulic pressure introduced into the two pressure chambers 15 and 16 with the post 12 and the piston 14 fixed.

A bracket 18 is integrally fixed to the cylinder tube 13, and a vertical hinge pin 19 is fixed to the bracket 18. The hinge pin 19 and a bearing 20 interpose the bracket 18 with the bracket 18. An arm 21 is pivotably connected. Further, a vertical hinge pin 22 is similarly provided on the distal end side of the intermediate arm 21, and the distal arm 25 is pivotally connected to the intermediate arm 21 via the hinge pin 22 and the bearing 23. . That is, the bracket 18, the intermediate arm 21 and the distal arm 25 are connected to the hinge pins 19 and 22 and the bearing 2.
A so-called horizontal multi-joint type arm 11 having the hinge pin joints as joints is formed by being connected to each other so as to be rotatable about a vertical axis via 0 and 23.

The bracket 18 is provided with two bush portions 26 at upper and lower positions.
6 is slidably mounted on a guide rod 27 provided in parallel with the post 12, so that the rotation of the cylinder tube 13 with respect to the post 12 is stopped.

As will be described later, the foremost shaft hole 28 of the tip arm 25 functions as a load generating point,
As shown in FIG. 1, a chain 30 which is suspended from the fork F of the vehicle T and includes a load cell 29 in the middle is connected to the shaft hole 28.

The output of the load cell 29 is taken into the control panel 32 together with the output of a rear wheel (steering wheel) lift detecting device 31 described later. As shown in FIG. 1, the control panel 32 includes an operation panel 33 including various operation units for controlling the hydraulic pressure of each of the hydraulic cylinders 9 and 10 and speed control, an indicator lamp, and the like, and a measurement signal processing circuit 34. A load value display 35 and a printer 36 are built in, and the output of the load cell 29 is taken into a measurement signal processing circuit 34.

FIG. 5 shows the second and third load generators 6,
The second and third load generating devices 6 and 7 are mounted on a tip of the horizontal multi-joint type arm 38 which is guided and supported by a post 37 so as to be able to move up and down. And a trunnion type towing cylinder (hydraulic cylinder) 39.

More specifically, a vertical post 37 is erected on the floor 1, and a bracket 41 integrated with the elevating guide 40 is supported by the post 37 so as to be able to move up and down. Is post bottom 4
It is suspended and supported via a chain 45 by an upper crane 44 so that a predetermined tension is applied to a chain 43 connecting the two. Note that the post 37 is also supported by an upper beam (not shown) on the building side.

A vertical hinge pin 46 is fixed to the bracket 41. An intermediate arm 48 is attached to the bracket 41 via the hinge pin 46 and a bearing 47.
Are rotatably connected. Further, the intermediate arm 48
Similarly, a vertical hinge pin 49 is provided on the distal end side of the distal arm 51. The distal arm 51 is pivotally connected to the intermediate arm 48 via the hinge pin 49 and a bearing 50. A trunnion type towing cylinder 39 is mounted at the forefront.

That is, similarly to the first load generating device 5, the three members of the bracket 41, the intermediate arm 48 and the distal end arm 51 are connected to the hinge pins 46 and 49 and the bearing 4
A so-called horizontal multi-joint type arm 38 having the hinge pin joint as a joint is formed by being connected to each other so as to be pivotable about a vertical axis through the joints 7 and 50.

The bracket 41 is provided with bush portions 52 at two upper and lower positions.
2 is slidably mounted on a guide rod 53 provided in parallel with the post 37, so that the bracket 41 is prevented from rotating with respect to the post 37.

As will be described later, the clevis 54 at the tip of the piston rod of the towing cylinder 39 functions as a load generating point, and as in FIG. Is connected to the clevis 54.

Next, a test procedure performed by the turning angle test apparatus configured as described above will be described with reference to the flowchart of FIG.

First, in the longitudinal turning load test of the vehicle T, as shown in FIG. 1 and FIG. 6, a fork F of the vehicle T is fitted with a traction attachment 55 dedicated to the turning load test, and the towing is performed. The load cell 29 as a load sensor is suspended and supported by the attachment 55 (step S1 in FIG. 7). Then, the vehicle T is stopped on the inclined angle table 4 which has been set in a horizontal posture in advance, and the lower end of the load cell 29 and the shaft hole 28 at the tip of the arm 11 are formed with an appropriate length as shown in FIG. They are connected by a chain 30 (steps S2 and S3).

Further, the fork F of the vehicle T is set at an arbitrary height position, for example, a maximum lift position (step S).
4) The arm 11 is set at an arbitrary height position. At this time, the arm 11 is theta ₁ as shown in FIG. 9 about 30
It is desirable to adjust so that ° and θ ₂ are approximately 60 °. At the same time, a crane (not shown) is used to prevent the vehicle T from overturning.

Subsequently, the lift detecting device 31 for the rear wheel (steered wheel) W is set on the vehicle T (step S5). As shown in FIG. 10, the lift detecting device 31 has a light emitting device 58a and a light receiving device 58b of a photoelectric switch 58 disposed at both ends of a substantially U-shaped frame 57 so as to face each other so that the optical axes of the light emitting devices 58a and 58b coincide with each other. If the rear wheel W is installed so as to block the projection light between the light emitting and receiving devices 58a and 58b when the rear wheel W is in contact with the tilt angle base 4, the light blocking state is released simultaneously with the rising of the wheel W thereafter. Thus, the lifting of the rear wheel W can be promptly detected. Therefore, as shown in FIG. 11, each rear wheel W is sandwiched by a portion where the rear wheel W is actually in contact with the tilt angle base 4 so that the projector 58a and the light receiver 58b face each other in the axle direction of the rear wheel. Each time, the lift detecting device 31 shown in FIG. 10 is set.

Thereafter, the lift cylinder 9 for driving the tilt angle table shown in FIG. 3 is operated, and the tilt angle table 4 is tilted to a standard angle (step S6).

Next, the lifting / lowering cylinder 10 of the first load generating device 5 is operated at a high speed to pull the chain 30 downward, while checking the load cell load value displayed on the display 35 and the tension of the chain 30. A predetermined tension is applied to the chain 30 (Step S7). At this time, arm 1
The shaft hole 28, which is the connection between the chain 1 and the chain 30, functions as a load generating point, and at the same time, the connection between the traction attachment 55 and the load cell 29 functions as a load application point 59,
The load applied to the chain 30 as a tensile force is detected by the load cell 29 and is displayed on the display 35 of the control panel 32 in real time.

When the chain 30 is pulled downward as described above and the chain 30 has an appropriate tension, the lifting cylinder 10 is switched to low-speed operation.
The downward load is continuously applied to the fork F of the vehicle T via the chain 30 while still increasing the load (steps S8 and S9). At this time, even if the attitude of the vehicle T changes due to the sinking of the load of the vehicle T or the like, the intermediate arm 21 and the tip arm 25 forming the arm 11 respond to the change in the hinge pins 19 and 22. Turning around the center, the connecting portion (shaft hole 28) between the tip arm 25 and the chain 30, which is the load generating point, is displaced in the horizontal plane. Thus, regardless of the attitude change of the vehicle T and the magnitude of the load applied to the fork F, the direction of the chain 30 connecting the load generating point 28 and the load application point 59, that is, the direction of the load application line is always constant. It is kept vertical.

When one of the rear wheels W rises while the load is being applied to the vehicle T, the photoelectric switch 58 of the lift detection device 31 detects this. While the buzzer sounds in response to the output of the photoelectric switch 58, the traction operation by the first load generating device 5 is automatically stopped, and the measurement signal processing circuit 34 indicates the indicated value of the load cell 29 at the moment when the rear wheel W rises. Is held and stored by the peak halt function, and at the same time, the value is printed and output by the printer 36 (steps S10 and S11).

At this point, the vehicle T is in an unstable state even if it does not fall over, and the vehicle T is returned to its original state by operating the switch of the operation panel 33 immediately after the automatic stop of the above-mentioned towing operation. The state is restored and the test ends (steps S12 to S14).

As described above, according to the present embodiment, the load at the moment when the rear wheel W lifts up can be measured while increasing the load while the vehicle T is tilted at a predetermined angle. The reliability of the test data showing the correlation with the load is extremely high.

Here, the turning load test of the vehicle T in the left-right direction is basically performed in the same procedure as described above using the second or third load generating device 6 or 7. However, as shown in FIG.
The vehicle T is inclined with respect to the rotation center of the inclination angle table 4 due to
And it is set so as to be in the backward falling state.

[Brief description of the drawings]

FIG. 1 is a configuration explanatory diagram of an entire test apparatus showing a typical embodiment of the present invention.

FIG. 2 is an explanatory plan view of the test apparatus shown in FIG. 1;

FIG. 3 is an explanatory front view of FIG. 2;

FIG. 4 is a sectional view taken along the line AA of FIG. 2;

FIG. 5 is a sectional view taken along the line BB in FIG. 2;

FIG. 6 is an explanatory diagram when a load cell is set on a fork.

FIG. 7 is a flowchart showing a processing procedure of the test method of the present invention.

FIG. 8 is an explanatory diagram of a chain used in FIG. 1;

FIG. 9 is an explanatory plan view of an arm in the first load generating device.

FIG. 10 is a perspective view of a rear wheel lift detection device.

FIG. 11 is an explanatory diagram when the rear wheel lift detection device is set.

FIG. 12 is an explanatory diagram showing a posture of the vehicle during a lateral turning load test.

FIG. 13 is an explanatory view showing a conventional turning load test method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 3 ... Hinge pin 4 ... Inclination angle table 5 ... 1st load generator 6 ... 2nd load generator 7 ... 3rd load generator 10 ... Cylinder for raising / lowering (actuator) 11 ... Arm 28 ... Shaft hole (Load generation) Point) 29 ... Load cell (load sensor) 30 ... Chain (corrugated body) 31 ... Floating detection device 34 ... Measurement signal processing circuit 35 ... Display 36 ... Printer 38 ... Arm 39 ... Towing cylinder (linear actuator) 54: Clevis (load generation point) 55: Tow attachment 58: Photoelectric switch 59: Load application point T: Forklift (vehicle) F: Fork

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Mitsuo Mitsui 2 Takara-cho, Kanagawa-ku, Yokohama, Kanagawa Prefecture Inside Nissan Motor Co., Ltd. (72) Inventor Tetsuo Ishida 2 Takara-cho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Motor Co., Ltd. In-company (56) References JP-A-7-63656 (JP, A) JP-A-63-17436 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B66F 9/075- 9/24 G01M 17/00

Claims (7)

(57) [Claims] In a state in which a forklift to be tested is stationary on an inclined table, a fork of the forklift is pulled downward by a load generating means to gradually apply the test load while applying a predetermined test load. While the line connecting the load application point on the fork side and the load generation point on the load generating means side when the test load is applied is maintained in a vertical state. A turning load test method for a forklift, wherein a test load at a moment when a rear wheel is lifted is detected as a turning load. 2. A test forklift to be tested is stopped on a tilt angle table, and the forklift of the forklift is pulled downward by a load generating means to apply a predetermined test load and gradually increase the test load. While increasing
A forklift turning load test device configured to detect a test load at a moment when a rear wheel of a forklift lifts with the increase of the test load as a turning load, wherein a load on a fork side when the test load is applied. At least the load generating point on the load generating means side has a degree of freedom of movement in a horizontal plane such that a line connecting the point of action and the load generating point on the load generating means side is always in a vertical state. Angular load test equipment for forklifts. 3. The load generating means is such that a tip of a horizontal articulated arm driven up and down by an actuator functions as a load generating point, or a linear actuator is provided at a tip of the horizontal articulated arm. 3. An apparatus according to claim 2, wherein the end of the output rod of the actuator functions as a load generating point. 4. A cable connecting a load application point on the fork side and a load generation point on a load generating means side, and a load sensor for detecting a test load applied to the cable. 4. The rolling load test apparatus for a forklift according to claim 3, wherein: 5. A lift detecting means for detecting a moment when a rear wheel of a forklift to be tested is lifted, and outputs of the lift detecting means and a load sensor are respectively input to the load sensor at a moment when the rear wheel is lifted. The turning load test apparatus for a forklift according to claim 4, further comprising measurement signal processing means for holding and storing the indicated value. 6. The fork according to claim 5, wherein the fork is provided with a traction attachment for a turning load test, and a part of the traction attachment functions as a load application point on the fork side. Rolling load test equipment for forklifts. 7. The forklift rolling angle load test apparatus according to claim 6, wherein the inclination angle of the inclination angle table can be arbitrarily adjusted.