JP2524187Y2 - Axle fixing device for industrial vehicles - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting structure for an axle rotatably supported on a body of a forklift or the like, for example, an industrial vehicle, and more particularly to an axle fixing device for an industrial vehicle.

[0002]

2. Description of the Related Art The applicant of the present invention has proposed an axle fixing device for an industrial vehicle, which will be described below (Japanese Patent Application Laid-Open No. 58-214406). As shown in FIG. 8, a support bracket 61 is formed to extend from the lower surface of the vehicle body 60,
The rear bracket 6 is attached to the support bracket 61 by a rotation shaft 62.
An axle 64 that rotatably supports 3 is swingably supported. Shock absorbers 65a, 65 for damping the swing of the axle 64 are provided on the left and right sides of the lower surface of the vehicle body 60.
b are arranged respectively, and both shock absorbers 65
The lower end of a rod 67 fixed to the piston 66 of a, 65b is in contact with the upper surface of the axle 64, and the piston 66 and the rod 67 are constantly urged downward by a spring 68.

The two shock absorbers 65a, 65
The upper cylinder chambers 69a and 69b of b are connected to each other by a hydraulic line 70, and a solenoid valve 71 is provided in the middle of the hydraulic line 70. The solenoid valve 71 controls the passage between the upper cylinder chambers 69a and 69b. The solenoid 72 of the solenoid valve 71 is connected to a control circuit 73, and the solenoid valve 71 is switched between a communication port 74 and a cutoff port 75.
6,77 are incorporated.

When the control circuit 73 is turned on and a voltage is output from the control circuit 73, the solenoid 72 of the solenoid valve 71 is excited to switch from the communication port 74 to the cutoff port 75. When switching from the communication side port 74 to the cutoff side port 75, both upper cylinder chambers 6
The communication between the shock absorbers 9a and 69b is cut off, the rods 67 of the shock absorbers 65a and 65b are fixed to the vehicle body 60, and the axle 64 cannot rotate.

The turning-on operation of the control circuit 73 is performed when the turning angle sensor 79 connected to the control circuit 73 and detecting the turning angle of the steering wheel 78 detects a turning angle exceeding a predetermined value. And is performed when a vehicle speed sensor 80 that detects a vehicle speed during traveling detects a vehicle speed equal to or higher than a predetermined value. That is, the control circuit 73 determines that the forklift is turning when the two sensors 79 and 80 are equal to or greater than a certain value.
The axle 64 is made unrotatable to prevent the vehicle body 60 from tilting. Therefore, the vehicle body does not tilt during the turning travel of the forklift, so that the forklift can travel stably.

[0006]

However, the axle fixing device mounted on the forklift does not allow the axle 64 to rotate with respect to the vehicle body 60 when the forklift turns, so that the vehicle body 60 is not tilted.
At this time, for example, when the forklift makes a right turn, if the traveling road surface has a slope that rises to the right with respect to the traveling direction of the forklift, the vehicle body 60 travels in a state of being inclined to the left. That is, the center of gravity of the vehicle body 60 moves to the left from the vehicle center.

[0007] Not only forklifts but also automobiles and motorcycles can perform stable running when the center of gravity is moved from the center of the vehicle body to the turning direction when turning, but the tilting of the vehicle body 60 is restricted as described above. When the vehicle turns and the center of gravity moves to the opposite side to the turning direction, the body 60 tilts to the opposite side to the turning direction by the action of the centrifugal force. Body 60
When the vehicle is tilted in the direction opposite to the turning direction, the rear wheel 63 on the right side rises in the turning direction, that is, referring to FIG. In addition, when carrying out the cargo handling work while holding the fork at a high position, the center of gravity of the body 60 of the forklift is moved upward with the rise of the fork.
The stability of the cargo became poor, which sometimes hindered cargo handling.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide an industrial vehicle capable of maintaining the ground contact of wheels with respect to a running road surface at all times and improving vehicle body stability. An object of the present invention is to provide an axle fixing device.

[0009]

According to the present invention, in order to achieve the above object, an axle to which wheels are connected, and an axle attached to the axle and rotatably supported by a vehicle body to support the axle. A rotating shaft rotatably supported on the vehicle body, an inner wheel connected and fixed to both ends of the rotating shaft, and a clutch mechanism rotating in one direction with respect to the two inner wheels but in different directions. An axle fixing device for an industrial vehicle, comprising: an outer wheel that is supported so as to be held, a brake device that is sandwiched from both side surfaces of the outer wheel and disables rotation of the outer wheel, and operating means that appropriately operates the brake device. I do.

[0010]

Therefore, according to the present invention, the rotation of the axle, which is connected to the wheels and is rotatably supported on the vehicle body by the rotation shaft, is performed by the inner ring connected to the both ends of the rotation shaft. On the other hand, it is regulated by making the outer wheels rotatably supported in one direction and different directions rotatable by the brake device unrotatable. The operation of the brake device is appropriately operated by operating means.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in a forklift will be described below with reference to FIGS. As shown in FIG. 3, a tilt cylinder 2 is attached to a front portion of the body 1 of the forklift, and supports the outer mast 3 so as to be tiltable in the front-rear direction. An inner mast 5 is arranged inside the outer mast 3 so as to be able to move up and down as the lift cylinder 4 expands and contracts. A sprocket 6 is rotatably mounted on the inner side of the inner mast 5.

A chain 7 is mounted on the sprocket 6, and a lift bracket 9 to which a fork 8 is attached and fixed is suspended from the chain 7. A lift bracket 9 to which the fork 8 is attached and fixed is moved up and down by a chain 7 that is wound or unwound as the inner mast 5 is moved up and down. A height sensor 10 composed of a rotary encoder is connected to a sprocket 6 which is rotatably mounted on the inner side of the inner mast 5. The height sensor 10 is a winding or unwinding amount of the chain 7, that is, a sprocket. A pulse corresponding to the amount of rotation of the fork 8 is generated, and the lift position of the fork 8 is detected.

A steering wheel 12 provided in a driver's cab 11 is rotatably supported by a steering shaft 13, and a steering gear (not shown) is attached to a lower end of the steering shaft 13. I have. The steering gear is connected to a rear wheel 14 via a steering device (not shown), and the rear wheel 14 is turned in the traveling direction of the forklift with the turning operation of the steering wheel 12. I have. That is, the rear wheel 1
Reference numeral 4 denotes a steering wheel and a driven wheel. On the other hand, a front wheel 15 of the forklift is a driving wheel connected to a driving force source (not shown) via a power transmission mechanism (not shown).

Further, a steering angle sensor 16 composed of a rotary encoder for detecting the angle of the steering wheel 12 is mounted between the steering shaft 13 and the body 1. Further, the forklift is equipped with a vehicle speed sensor 17 for detecting the traveling speed of the forklift. As shown in FIG. 1, the rear wheel 14 is rotatably supported by an axle 19 as an axle by a kingpin 18. At the center of the axle 19 is a center pin 20 as a rotation axis.
The center pin 20 is rotatably supported with respect to the rear portion of the body 1. That is,
The axle 19 is connected to the body 1 via a center pin 20.
Is rotatably supported. At both left and right end portions between the body 1 and the axle 19, a shock absorbing spring and a shock absorber (both not shown) for damping the shock absorbing spring are attached. Is urged downward.

One-way clutches 21 and 22 are provided at both ends of the center pin 20, respectively. The one-way clutches 21 and 22 include inner rings 23 and 24 fixedly attached to ends of a center pin 20, and inner rings 23 and 24, respectively.
24, outer rings 25, 26 and inner rings 23, 2
4 and a clutch connecting member (not shown) disposed between the outer rings 25 and 26. The clutch connecting members move the outer rings 25 and 26 one-to-one with respect to the inner rings 23 and 24.
It can rotate only in the direction.

The outer race 25 of the one-way clutch 21 on the rear side (front side in FIG. 1) rotates only clockwise with respect to the inner race 23 and cannot rotate counterclockwise. The outer ring 26 of the one-way clutch 22 on the front side rotates only counterclockwise with respect to the inner ring 24 in the figure, and does not rotate clockwise.

The body 1 has one-way clutches 21 provided at both ends of the center pin 20.
22 are sandwiched between the outer races 25 and 26 from both sides.
Brake devices 27 and 28 for disabling rotation of the wheels 5 and 26 are mounted and fixed. The brake devices 27 and 28 are provided with brake pads (not shown) disposed on both side surfaces of the outer races 25 and 26, a piston (not shown) for pressing the brake pads, and a slide between the brake pads and the pistons. It is constituted by a piston bracket 29 and the like which are supported and attached to the body 1 as possible.

The projecting operation (braking operation) of the pistons of the brake devices 27, 28 is performed by the brake devices 27, 2
The operation is performed by the hydraulic pressure of the brake fluid that is pressure-fed from master cylinders 31 and 32 that are individually connected to each other via a brake hose 30 that is connected to the pipe 8. That is, by compressing the piston rods 33 and 34 of the master cylinders 31 and 32, the brake fluid in the cylinders 31 and 32 is pressure-fed to the brake devices 27 and 28 via the brake hose 30, and the brake devices 27 and 28 are compressed. , 28 are projected.

The compression operation of the piston rods 33 and 34 of the master cylinders 31 and 32
The operation is performed by the projecting operation of the plungers 37, 38 of the solenoid valves 35, 36 as operating means connected to the solenoids 3, 34. The projecting amounts of the plungers 37, 38 of the two solenoid valves 35, 36 are determined in three stages: a projecting amount of zero, a projecting amount 1 and a projecting amount 2.

When the plungers 37, 38 have zero protrusion, the piston rods 33, 34 of the master cylinders 31, 32 are at the C position. When the plungers 37, 38 have one protrusion, the piston rods 33, 34 of the master cylinders 31, 32 have.
Is the position B, and when the protrusion amount is 2, the positions of the piston rods 33, 34 of the master cylinders 31, 32 move to the position A.

When the piston rods 33, 34 of the master cylinders 31, 32 are at the C position, no brake fluid is fed to the brake devices 27, 28 and the pistons of the brake devices 27, 28 do not project. I have. When the piston rods 33 and 34 are at the position B, brake fluid is supplied to the brake devices 27 and 28 at a low pressure. Therefore,
The pistons of the brake devices 27 and 28 hold the outer races 25 and 26 of the one-way clutches 21 and 22 at low pressure (weak force).
When the outer races 25 and 26 of the outer race 22 are pinched, the outer race 2
5 and 26 are in a state where they are difficult to rotate with respect to the brake devices 27 and 28.

Further, when the piston rods 33 and 34 are at the position A, the brake fluid is supplied to the brake devices 27 and 28 at a high pressure. Therefore, the pistons of the brake devices 27 and 28 are high pressure (strong).
The outer rings 25 and 26 of the one-way clutches 21 and 22 are held between the two-way clutches 21 and 22.
When the outer races 25 and 26 are pinched, the outer races 25 and 26 cannot rotate with respect to the brake devices 27 and 28.

Next, the electrical configuration of a forklift equipped with the axle fixing device will be described with reference to the block diagram of FIG. A controller 39 for performing various controls is mounted in the body 1 of the forklift.
Is a lift counter 42 and a steering counter 41
Central processing unit (hereinafter, referred to as CPU) 40, ROM 43 storing control programs and the like in advance, and CPU
It comprises a RAM 44 and the like for temporarily storing the calculation results of 40 and the like.

The lift sensor 10 is connected to a lift counter 42 built in the CPU 40. The lift sensor 10 outputs a pulse corresponding to the amount of rotation of the sprocket 6 on which the chain 7 is mounted. Output to the application counter 42. When the CPU 40 determines that the count value of the lift counter 42 has reached the reference lift pulse number previously stored in the ROM 43, the CPU 40 sets the protrusion amounts of the plungers 37, 38 of both solenoid valves 35, 36 to zero. To 1 and both master cylinders 31, 3
The second piston rods 33 and 34 are pressed from the C position to the B position.

That is, the pistons of the two brake devices 27 and 28 are pressed by the compressive force (low pressure) of the piston rods 33 and 34 pressed to the B position of the master cylinders 31 and 32, and the front and rear one-way devices are pressed. Clutches 21 and 22
The rotation of the outer races 25 and 26 is regulated by a weak force. That is, when the lift position of the fork 8 is equal to or higher than a certain height, the body 1 is less likely to tilt left and right.

A steering angle sensor 16 is connected to a steering counter 41 built in the CPU 40. The steering angle sensor 16 sends a pulse corresponding to the angle of the steering wheel 12 to the steering counter 41. Output. When the CPU 40 determines that the count value of the steering counter 41 has reached the reference disconnection angle pulse stored in the ROM 43 in advance, the plunger 37 of the solenoid valve 35 connected to the one-way clutch 21 on the rear side, Alternatively, the projecting amount of the plunger 38 of the front solenoid valve 36 is set to 2, and the piston rod 33 of the master cylinder 31 or the master cylinder 3
The second piston rod 34 is pressed to the position A.

That is, the brake device 27 (2
8) is pressed by the compression force (high pressure) of the piston rod 33 (34) pressed to the position A of the master cylinder 31 (32), and the outer ring 25 of the rear (front) one-way clutch 21 (22) is pressed. (26) Only the rotation is strongly regulated. The brake device 27 (28) on one side that operates at this time turns the steering wheel 12 clockwise to make a right turn, for example, and the CPU
When it is determined by 40 that the pulse number output from the steering angle sensor 16 has reached the reference angle pulse number, the rear brake device 27 is operated and the steering wheel 12 is turned counterclockwise to make a left turn. When the CPU 40 determines that the number of pulses output from the steering angle sensor 16 has reached the reference angle pulse number by the CPU 40, the front brake device 28 operates.

Therefore, in FIG. 4, when the forklift turns right, the axle 19 cannot rotate clockwise with respect to the body 1 and can turn counterclockwise. The axle 19 cannot rotate counterclockwise with respect to the body 1 and can rotate clockwise. That is, when the forklift turns right, the body 1 can tilt to the right with respect to the axle 19 and cannot tilt to the left, and when turning left, the body 1 moves to the left with respect to the axle 19. To the right and to the right.

Further, a vehicle speed sensor 17 is connected to the CPU 40. The vehicle speed sensor 17 detects the vehicle speed of the forklift, and outputs a vehicle speed detection signal corresponding to the vehicle speed to the CPU 40. Then, the CPU 40 inputs a vehicle speed detection signal from the vehicle speed sensor 17, and when the vehicle speed detection signal is determined to be zero, that is, when it is determined that the forklift has stopped, the plungers 37, 38 of the two solenoid valves 35, 36 determine the amount of protrusion. 2 and both master cylinders 3
The first and second piston rods 33 and 34 are pressed to the position A.

That is, the pistons of both brake devices 27 and 28 are pressed by the compressive force (high pressure) of the piston rods 33 and 34 pressed to the position A of the master cylinders 31 and 32, and the front and rear one-way clutches are pressed. The rotation of the outer races 25 and 26 of 21 and 22 is strongly controlled. That is, when the forklift stops, the body 1 is not tilted left and right.

Next, the operation of the forklift having the above configuration will be described with reference to the flowchart of FIG. First, in step 101, the CPU 40 determines whether or not the detection value of the vehicle speed sensor 17 is zero. That is, it is determined whether the forklift is stopped or running. Then, when it is determined that the vehicle speed is zero, that is, the forklift is stopped, the routine proceeds to step 102, where the amount of protrusion of the plungers 37, 38 of both solenoid valves 35, 36 is set to 2
Then, the piston rods 33, 34 of the master cylinders 31, 32 are pressed to the position A.

That is, both the rear and front brake devices 2
The brake fluid is sent to the first and second one-way clutches 21 and 22 from both sides of the outer wheels 25 and 26 via the brake pads. I do. Therefore,
The axle 19 cannot rotate with respect to the body 1. That is, the center pin 20 fixed to the axle 19
Are the one-way clutches 21 and 22 and the brake device 2
Since the forklift is fixed to the body 1 via 7, 28, the body 1 is not tilted left and right when the forklift stops.

On the other hand, in step 101, the CPU
When the detected value of the vehicle speed sensor 17 is not zero, that is, when the forklift is running, the process proceeds to step 103, and whether or not the lift counter 42 has counted the reference lift pulse number is determined. Determine. When it is determined that the lift counter 42 has counted the reference lift pulse number, the process proceeds to step 104, and the CPU 40
Are plungers 37, 3 of both solenoid valves 35, 36
The protrusion amount of 8 is set to 1, and the piston rods 33, 34 of both master cylinders 31, 32 are pressed to the B position.

That is, both the rear and front brake devices 2
The brake fluid is supplied to the first and second one-way clutches 21 and 22 from both side surfaces of the outer wheels 25 and 26 through the brake pads with low force. Pinch. Therefore,
The axle 19 is less likely to rotate with respect to the body 1, and the center pin 20 fixedly connected to the inner rings 23, 24 of the two-way clutches 21, 22 is also less likely to rotate accordingly. That is, the body 1 is less likely to rotate with respect to the axle 19. That is, when the lift position of the fork 8 is higher than the reference lift position during traveling of the forklift, the body 1 is hardly tilted left and right.

On the other hand, in step 103, the CPU
Reference numeral 40 denotes a case where the count value of the lift counter 42 is less than the reference lift pulse, that is, when the lift position of the fork 8 is lower than a preset position (reference lift position). Move to step 105. In step 105, the CPU 40 determines the rotation direction of the steering wheel 12 and whether or not the steering counter 41 has counted the reference turning angle pulse number.

When the CPU 40 determines that the steering counter 41 has counted the reference turning angle pulse number, it proceeds to step 106, and determines that the rotation direction of the steering wheel 12 is clockwise, that is, that the forklift is running clockwise. In this case, the protrusion amount of the plunger 37 of the solenoid valve valve 35 connected to the rear brake device 27 is set to 2, and the master cylinder 31
Is pushed to the position A.

That is, the brake fluid is sent under pressure to the rear brake device 27 at a high pressure, and the piston of the brake device 27 is strongly clamped from both sides of the outer ring 25 of the rear one-way clutch 21 via the brake pads. . Therefore, the outer wheel 25 of the rear one-way clutch 21 is fixed to the body 1 via the rear brake device 27 and cannot rotate. However, at this time, the front brake device 28 is not operated, and the front one-way clutch 22 is free.
0 can only rotate counterclockwise in FIG.

Therefore, the axle 19 can rotate only counterclockwise with respect to the body 1. That is, in FIG. 4, the body 1 can tilt only to the right with respect to the axle 19. Then, at this time, for example, when the forklift travels on a traveling road surface having a slope rising to the right with respect to the traveling direction, the body 1 moves rightward with respect to the axle 19 around the center pin 20 as shown in FIG. To tilt. That is, the center of gravity of the forklift moves from the center of the body 1 to the right side, which is the turning direction. Further, at this time, the body 1 is not tilted to the left side, which is not the turning direction, regardless of the presence or absence of the gradient on the traveling road surface. Therefore, when the forklift makes a right turn, the ground contact between the traveling road surface and the front wheels 15 and the rear wheels 14 is maintained.

On the other hand, when the CPU 40 determines that the rotation direction of the steering wheel 12 is counterclockwise, that is, that the forklift is running to the left, the plunger 38 of the solenoid valve valve 35 connected to the front brake device 28 projects. The master cylinder 32
Is pushed to the position A. That is, the brake fluid is pressure-fed to the front brake device 28 at a high pressure, and the piston of the brake device 28 is strongly clamped from both sides of the outer ring 26 of the front one-way clutch 22 via the brake pads. Therefore, the outer wheel 26 of the front one-way clutch 22 is fixed to the body 1 via the front brake device 28, and cannot rotate.
However, at this time, since the rear brake device 27 is not operated and the rear one-way clutch 21 is free, the center pin 20 can rotate only clockwise in FIG. Therefore, axle 19
Can rotate only clockwise with respect to the body 1. That is, in FIG. 4, the body 1 can tilt only to the left with respect to the axle 19.

At this time, for example, when the forklift travels on a traveling road surface having a slope rising leftward with respect to the traveling direction, the body 1 moves with respect to the axle 19 around the center pin 20 as shown in FIG. Tilt to the left.
That is, the center of gravity of the forklift moves from the center of the body 1 to the left, which is the turning direction. At this time, the body 1
Is not tilted to the right, which is not the turning direction, regardless of the presence or absence of the slope of the traveling road surface. Therefore, when the forklift is turning left, the traveling road surface and the front wheels 15 and the rear wheels 14
And the grounding property is maintained.

As described in detail above, according to the forklift equipped with the axle fixing device of the present embodiment, the axle 19
One-way clutches 21 and 22 having outer rings 25 and 26 having different rotation directions are provided at both ends of a center pin 20 which is supported so as not to be rotatable, and brake devices 27 and 28 rotate the outer rings 25 and 26. Is regulated, when the forklift turns, the body 1 is tilted only in the turning direction, so that the stability of the body 1 during the turning operation is improved.

Further, even if the fork 8 is at a high position and the center of gravity of the body 1 moves upward, the body 1 is hardly tilted to the left and right, so that the stability of the body 1 is improved even during cargo handling work. You. The present invention is not limited to the above-described embodiment, and may be configured as follows without departing from the spirit of the present invention.

(1) In the above embodiment, when the output signal of the vehicle speed sensor 17 is zero, the controller 39 determines that the forklift is stopped, and controls both solenoid valves 35 and 36 as operating means. But
Instead of the output signal of the vehicle speed sensor 17, for example, a parking brake may be activated, and the stop state of the forklift may be determined based on a signal output to the controller 39 when the parking brake is activated. .

(2) In the above embodiment, when the number of pulses output from the height sensor 10 exceeds the reference value, the two solenoid valves 35 and 36 as operating means are controlled by the controller 39. This lift sensor 10
Instead of the number of pulses output from the controller 3, the controller 3 is operated when the lift lever for operating the lift cylinder 4 is operated.
9 may be configured to control the solenoid valves 35, 36.

(3) In the above embodiment, the projections of the plungers 37, 38 of the solenoid valves 35, 36 as operating means are set in three stages of zero, one, and two. You may comprise so that it may be performed continuously according to the information of each sensor.

[0046]

As described above in detail, according to the present invention, there is an excellent effect that the ground contact of the wheels is constantly maintained on the traveling road surface, and the stability of the vehicle body can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of an axle and a brake device showing an embodiment of the present invention, and a front view showing a master cylinder and a solenoid valve.

FIG. 2 is a block diagram showing an electrical configuration of the axle fixing device.

FIG. 3 is a side view showing a schematic configuration of a forklift.

FIG. 4 is a rear view of the forklift.

FIG. 5 is a rear view of the forklift showing a state where the forklift is traveling on a traveling road surface having a right slope.

FIG. 6 is a rear view of the forklift showing a state where the forklift is traveling on a traveling road surface having a left slope.

FIG. 7 is a flowchart showing an operation performed by a controller.

FIG. 8 is a schematic diagram illustrating a hydraulic circuit and a mechanical configuration of an axle fixing device provided in a conventional forklift.

FIG. 9 is a rear view of the forklift showing a state where the conventional forklift is traveling on a traveling road surface having a slope.

[Explanation of symbols]

1 ... body as body, 14 ... rear wheel as wheels, 1
9: axle as axle, 20: center pin as rotating shaft, 23: inner ring, 24: inner ring, 25: outer ring, 26
... Outer ring, 27 ... Brake device, 28 ... Brake device, 3
5 ... solenoid valve as operating means, 36 ... solenoid valve as operating means.

Claims (1)

(57) [Scope of request for utility model registration] An axle connected to wheels, a rotating shaft attached to the axle, rotatably supported by the vehicle body, and rotatably supporting the axle with respect to the vehicle body; An inner ring connected and fixed to both ends of the rotation shaft, an outer ring supported by the clutch mechanism in one direction with respect to the two inner rings and rotatably supported in different directions, and sandwiched from both side surfaces of the outer ring; And an axle fixing device for an industrial vehicle, comprising: a brake device that disables rotation of the outer wheel; and operating means for appropriately operating the brake device.