JP3888610B2 - Lift truck braking device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a lift truck braking device.
[0002]
[Prior art]
  In general, a lift truck is provided with a traveling device for traveling the vehicle body and a braking device for stopping the traveling of the vehicle body. As this braking device, a mechanical braking device is mainly used, and a traveling motor of the traveling device is used. An electric braking method may be used in combination.
[0003]
  The mechanical braking device is configured to press a wear-resistant member such as a brake shoe or brake pad against a rotating body linked to a traveling motor, drive wheel, etc., and brake the rotating body by friction, and press the wear-resistant member against the rotating body. As a method for doing this, a method using an electric device such as an electromagnet and a method using a mechanical mechanism are common, but a method using a hydraulic device can also be adopted.
[0004]
  In any case, the brake device is provided with an operation tool for the operator to operate the brake, i.e., the brake operation tool, and the lift truck brake device is a model that the operator operates while walking near the vehicle body. For example, a brake pedal is provided as the brake operation tool.
[0005]
  By the way, there are two types of lift trucks that the operator gets on and drives while the operator sits on the driver's seat and the operator operates while standing on the cab. In the latter, the brake pedal is at the brake release position. When the brake pedal is stepped on, the brake action is released, and a so-called deadman type braking device is employed in which the brake is actuated when the brake pedal is depressed more shallowly or when the brake pedal is not depressed.
[0006]
[Problems to be solved by the invention]
  In a lift truck employing this deadman type braking device, it is necessary to keep the brake action released by continuously stepping on the brake pedal in order to travel.
[0007]
  However, in this deadman type braking device, in order to make the braking device respond quickly when the operator depresses or releases the brake pedal, the brake pedal is always placed at the maximum braking position where the braking force is maximized. An urging spring is provided.
[0008]
  Therefore, the operator must continue to depress the brake pedal against the spring while traveling, which places a heavy work load on the operator. In particular, operators with weak operating skills, such as female operators, elderly operators, and operators with physical dysfunction, which have increased in recent yearsInThe heavy labor load is a problem.
[0009]
  Of course, in the case of a braking device in which the wear-resistant member is driven by an electric device such as an electromagnet or a hydraulic device, the operating force of the brake pedal can be weakened by setting the elasticity of the spring that biases the brake pedal in the opening direction. However, in a braking device configured such that the wear-resistant member is driven by a brake pedal via a mechanical mechanism, it is necessary to press the wear-resistant member against the rotating body at a predetermined pressure or higher. Cannot be weakened beyond a certain level.
[0010]
  SUMMARY OF THE INVENTION An object of the present invention is to provide a lift truck braking device that solves the problems of the prior art and can reduce the labor load of an operator.
[0011]
[Means for Solving the Problems]
  The present invention provides a braking apparatus for a lift truck provided with a brake pedal provided for operating a deadman brake on a cab on which an operator gets on,Brake release detection means for detecting that the brake pedal is depressed to the brake release position, urging means for urging the brake pedal in the depression direction, and presence / absence of operation of the accelerator means of the lift truck are detected. The accelerator operation detecting means and the brake release detecting means detect that the brake pedal is depressed to the brake release position, and the accelerator operation detecting means detects that the accelerator means is being operated. The urging means is actuated to urge the brake pedal in the depression direction, and the brake pedal is depressed to the brake release position when the brake pedal is not depressed to the brake release position or by the brake release detection means. Is detected by the accelerator operation detecting means. Assist means and a help control means so as not to perform energization of the depression direction of the brake pedal by the biasing means is provided when the serial accelerator means detects that not operatedIt is characterized by that.
[0012]
  As a result, if the brake pedal is depressed to the brake release position,Helping meansSince the urging force counters a part of the elasticity of the spring that urges the brake pedal in the braking action direction, the force necessary for the operator to keep stepping on the brake pedal to the brake release position is reduced.
[0013]
  In the present invention, the assisting means has a brake pedal brake.CancelThe assisting means urges the brake pedal in the depressing direction when the brake pedal is in the position, but the urging force of the assisting means applies the brake pedal in the releasing direction in order to make the braking device respond quickly to the brake operation of the operator. It is necessary to set it weaker than the spring. However, when the brake pedal is not depressed to the brake release position, the assisting means does not urge the brake pedal, so that the assisting means does not hinder the brake operation.
[0014]
  By the way, the traveling of the lift truck includes power running that energizes the traveling motor to drive the drive wheels by the traveling motor, and coasting that travels by the inertia of the vehicle body including the load, and requires a delicate braking operation especially during coasting. Therefore, it is preferable to reduce the resistance to the braking operation. In addition, since the running by the coasting operation is a relatively short time, the effort to keep stepping on the brake pedal is hardly a problem.
[0015]
  Further, the accelerator means is not operated while the vehicle is stopped, and the assisting means is not utilized because the brake pedal is positioned at the maximum brake operating position to hold the vehicle body stopped. .
[0016]
  Therefore, in the present invention, the assisting means can be operated only when the accelerator means of the lift truck is operated, and wasted energy spent for monitoring the position of the brake pedal, for example, when the assisting means is unnecessary. Reduce consumptionis doing.
[0017]
  The assisting means of the present invention comprises brake release detecting means for detecting that the brake pedal is depressed to the brake release position.,Depending on whether the brake pedal is in the brake release positionHelping meansIn order to perform on / off control, it is advantageous to provide this brake release detecting means.
[0018]
  The brake release detection means may be configured to be driven by a brake pedal of the brake device or a mechanical mechanism component interlocked therewith so as to detect that the brake pedal is located at the brake release position.
[0019]
  For example, a switch such as a contact switch represented by a micro switch, a knife switch, or a non-contact switch represented by a proximity switch, or a sensor such as a pressure sensor, a photo sensor, an acoustic sensor, or an ultrasonic sensor may be used as the brake release detection means. However, other than these, measuring means such as a potentiometer and a rotary encoder can be used as the brake release detecting means.
[0020]
  When the wear resistant member of the braking device is driven by an electric actuator, the brake release detecting means can be constituted by an energization detecting means for detecting energization to the electric actuator, and the wear resistant member of the braking device is hydraulically operated. When driven by an actuator, a hydraulic sensor that detects the supply pressure to the hydraulic actuator that drives the wear-resistant member, and a position sensor that detects position switching of a control valve that controls the supply and discharge of pressure oil to and from the hydraulic actuator Alternatively, the brake release detecting means can be configured by an energization sensor that detects energization of an electromagnetic control valve that controls supply and discharge of pressure oil to and from the hydraulic actuator.
[0021]
  The assisting means of the present invention includes an urging means for urging the brake pedal located at the brake release position in the depression direction.,As this urging means, a spring can be used, but a rotational drive means such as an electric motor, a rotary solenoid, and a hydraulic motor, a linear drive means such as a linear motor, a linear solenoid, an electric cylinder, and a hydraulic cylinder, and an electromagnet It is advantageous to use a suction means or a suction means such as a magnet to be included because the configuration can be simplified.
[0022]
  Helping means of the present inventionIsThe brake release detecting means and the biasing meansPrepared,Assisting control means for operating the urging means when the brake release detecting means detects that the brake pedal is depressed to the brake release position..As the assist control means, a means provided with a microcomputer or a switch circuit that opens and closes depending on whether or not the brake release detecting means is energized may be used.
[0023]
  By the way, in the present invention, as a method for enabling the assisting means to operate only when the accelerator means of the lift truck is operated, the presence or absence of the operation of the accelerator means is detected, and the assisting means is detected only when the accelerator operation is detected. There is a method of enabling the operation, and among these methods, there are a method of turning on / off the assist control means of the assist means and a method of turning on / off the energization or pressure oil supply to the urging means.
[0024]
  In order to implement these methods, anyway, an accelerator operation detecting means for detecting the presence or absence of an accelerator operation is provided. As this accelerator operation detecting means, an energization detecting means for detecting the presence or absence of energization to the traveling motor may be adopted,Accelerator meansFor example, to the assist control means configured to activate the microcomputer of the assist means, the switch circuit that is opened and closed depending on whether the brake release detecting means is energized, and the travel operation detecting means. It is only necessary to employ assisting control means in which a switch circuit that is opened and closed depending on whether or not current is supplied is connected in series.
[0025]
  thisAccelerator operation detection meansIsAccelerator meansAlternatively, it may be configured so that it can be detected that the traveling operation means is traveling by being driven by a component interlocked therewith.
[0026]
  The brake release detecting means isFor example, switches such as contact switches represented by microswitches, knife switches, contactless switches represented by proximity switches, pressure sensors, photosensors, acoustic sensors, ultrasonic sensors, etc.TheIn addition to these, measuring means such as a potentiometer and a rotary encoder may be used as the brake release detecting means.
[0027]
  In the present invention, as another method for enabling the assisting means only when the accelerator means of the lift truck is operated, the assisting means can be a brake pedal or a mechanical mechanism interlocked therewith only when the accelerator means is operated. There is a method in which the brake pedal is energized by being linked to the parts and arranged at a position separated from the brake pedal or mechanical mechanism parts interlocked with the brake pedal when the accelerator means is not operated.
[0028]
  As apparent from the above description, the present invention is not limited to a brake device in which the wear-resistant member of the brake device is operated by a brake pedal via a mechanical mechanism, but also a brake in which the wear-resistant member is driven by an electric device or a hydraulic device. The present invention can also be applied to the device, and in these cases, it is free to make or not to weaken the elasticity of the spring that biases the brake pedal to the maximum brake operation position.
[0029]
DETAILED DESCRIPTION OF THE INVENTION
  A lift truck braking device according to an embodiment of the present invention will be described in detail with reference to the drawings.
[0030]
  FIG. 1 is a circuit block diagram of assisting means provided in a lift truck braking apparatus according to one embodiment of the present invention, and FIG. 2 is a perspective view of the lift truck. This lift truck is called a reach-type forklift. For example, as shown in FIG. 2, the vehicle body 1 of this lift truck includes a frame 2, a mast 3, a backrest 4 and a fork 5. A cockpit 6 in which an operator gets on the right rear is provided.
[0031]
  The frame 2 includes a rear frame 2a and a pair of left and right front frames 2b that extend in front of the left and right sides at an appropriate interval, and the rear frame 2a has left and right sides at the rear end in plan view. A quadrangular bottom frame 2c with corners chamfered, left and right side plates 2d and 2e raised on the left and right sides, and a front-rear intermediate portion of the bottom frame 2c and the left and right side plates 2d and 2e. And a connecting plate 2f to be connected. The front face of the cockpit 6 is partitioned from the battery housing portion by the connecting plate 2f, and the right face is partitioned from the outside by the right side face plate 2e. The left side of the cockpit 6 is divided into a power room by a first side panel 7 fixed to the connecting plate 2f and the bottom frame 2c of the frame 2, and is driven by a cab 8 stretched on the lower surface of the cockpit 6. It is partitioned from the space below it. Further, the rear and upper surfaces of the cockpit 6 are continuously opened.
[0032]
  An operation panel 10 is provided on the front side of the cockpit 6 so as to cover the upper surface of the battery storage unit. The operation panel 10 extends and retracts the mast 3 to move the backrest 4 and the fork 5 up and down. A tilt lever 12 that is operated to tilt the backrest 4 and the fork 5, a reach lever 13 that is operated to move the mast 3, the backrest 4 and the fork 5 back and forth, and the lift truck back and forth. Accelerator operating tools (generally referred to as accelerator levers) 14 that are operated in order to run the vehicle are provided in order from left to right.
[0033]
  The power room has a rear surface covered with a second side panel 9 that can be opened and closed, and an upper surface covered with a top panel 15. A steering handle 16 for controlling the traveling direction is provided above the top panel 15.
[0034]
  In this power room, a traveling motor, a hydraulic power unit, and the like are housed, and drive wheels 17 linked to the traveling motor via a speed reducer project downward from the lower surface of the opened power room to project the ground. It rolls up.
[0035]
  Further, a support wheel 18 is rotatably supported on each front frame 2b, and a free wheel 19 supported on the bottom frame 2c is provided below the cab 8.
[0036]
  The accelerator operating tool 14 is provided so as to be able to tilt back and forth around a neutral position standing upright with respect to the operation panel 10, for example, and when this is positioned at the neutral position, the travel motor stops. When the vehicle body 1 is stopped and tilted forward from the neutral position, the traveling motor rotates in the forward direction and the vehicle body 1 moves forward. When the vehicle body 1 tilts backward from the neutral position, the traveling motor rotates in the backward direction and the vehicle body 1 moves backward. . Now, this lift truck is provided with a braking device for braking the travel of the vehicle body 1.
[0037]
  3 is a side view of the braking device for the lift truck, FIG. 4 is a rear view of the braking device, and FIG. 5 is a plan view of the braking device. As shown in FIGS. 3 to 4, the braking device 20 includes a brake disc 21 fixed to the upper end portion of the shaft 19 a of the traveling motor 19, and an upper and lower 1 that contacts and separates the upper and lower surfaces of the brake disc 21. A pair of brake pads 22, a brake pedal 23 disposed near the driver's cab 8 at the left back of the cockpit 6, and a mechanical mechanism 24 for interlocking the brake pad 22 with the brake pedal 23 are provided.
[0038]
  As shown in FIGS. 3 and 5, a bracket 25 is fixed to the upper portion of the traveling motor 19, and a pair of holder arms 26 and 27 that are opened and closed up and down with the brake disc 21 sandwiched between the bracket 25. One end is pivotally supported, and the brake pads 22 are fixed to the surfaces of the holder arms 26 and 27 facing the brake disc 21 respectively.
[0039]
  As shown in FIG. 3, bolts 28 whose heads are received by the upper surface of the upper holder arm 26 are inserted into the free ends of the upper and lower holder arms 26, 27, and the lower holder arm 27, A spring 30 consisting of a compression coil spring is inserted between the spring seat 29 supported by the bolt 28 below and the holder arms 26 and 27 are always closed by this spring 30, and the brake pad 22 is The brake disc 21 is biased in the direction in which it is pressed against both surfaces (brake action direction).
[0040]
  A brake release cam 32 such as an elliptical cam, an egg-shaped cam, a triangular cam, an S-shaped or a Z-shaped cam, for example, is provided between the free ends of the holder arms 26, 27 via the bracket 25. When the distance between the free ends of the holder arms 26 and 27 is increased against the spring 30 by rotating the brake release cam 32, the brake pads 22 are separated from the brake disc 21. The brake action is released.
[0041]
  An adjuster screw 33 for receiving the brake release cam 32 is provided at the free ends of the holder arms 26 and 27. By adjusting the position where the adjuster screw 33 receives the brake release cam 32,When releasing the brakeThe distance between the disk 21 and the pad 22 is adjusted.
[0042]
  As shown in FIGS. 3 to 5, a support frame 2g raised in the power room in the vicinity of the first side panel 7 is fixed to the bottom frame 2c. The support frame 2g will be described later. In this way, the brake pedal 23 is, for example, a horizontal brake centered on its front end.CancelIt is supported so that it can rotate between the position and the braking action position where the rear end part jumps up.
[0043]
  The mechanical mechanism 24 may be configured so that the brake pad 22 is interlocked with the brake pedal 23. In this embodiment, as described below, the first rod 34, the bell crank 35, 2 rods 36 and a lever 37. First, the first rod 34 is provided with a length adjusting means 38 as necessary, and the lower end portion thereof is connected to, for example, an intermediate portion in the front-rear direction of the brake pedal 23.
[0044]
  The bell crank 35 has a rotating shaft 35a that is rotatably supported by the connecting plate 2f, and a rearward arm 35b and an upward arm 35c that are different from each other by about 90 ° in the swinging direction. The upper end portion of the first rod 34 is connected, and the front end portion of the second rod 36 is connected to the free end portion of the upward arm 35c. The second rod 36 is provided with a length adjusting means 39 as required, and the rear end thereof is the brake.CancelThe cam 32 is connected to the free end of the lever 37 fixed to the rotation center shaft 32 a of the cam 32.
[0045]
  According to the braking device 20, the operator brakes the brake pedal 23.CancelWhen the vehicle is stepped deeper than a certain distance toward the position, the first rod 34 is pulled downward, the second rod 36 is pulled forward via the bell crank 35, and the brake is applied via the lever 37.CancelThe cam 32 is driven to separate the brake pad 22 from the brake disc 21, and the braking action is released.
[0046]
  When the operator depresses the brake pedal 23 or removes the foot from the brake pedal 23, the spring 30 is braked.CancelThe cam 32 is pushed in a direction that reduces the amount of cam lift, and this brakeCancelWhen the brake pedal 23 rotates in conjunction with the cam 32 beyond a position on the brake action position side from the brake release position, the brake pad 22 is pressed against the brake disc 21 by the spring 32, and the brake action is effective.
[0047]
  When the operator only puts his / her foot on the brake pedal 23 but does not step on the brake pedal 23 or when the operator has withdrawn his / her foot from the brake pedal 23, the brake pedal 23 is pushed back to the brake operating position by the spring 32.
[0048]
  Therefore, according to this braking device 20, in order to run the vehicle body 1, it is necessary for the operator to press the brake pedal 32 more than a certain amount with a force applied to the foot to release the brake action, and the brake pedal 20 is depressed during the running. It is necessary to keep the state continuously.
[0049]
  The braking device 20 according to this embodiment is provided with an assisting means 40 that urges the brake pedal 23 in the depression direction when the brake pedal 23 is depressed during traveling, and assists the operator's depression. Has major features. As shown in FIG. 1, the assisting means 40 is configured so that the brake pedal 23 is urged in the depression direction when the vehicle is running and the brake pedal 23 is depressed to the brake release position. Brake release detecting means 41 for detecting that the pedal 23 is located at the brake release position, an urging means 42 comprising a rotary solenoid capable of urging the brake pedal 23 in the depression direction, and a driving power source for the urging means 42 The brake pedal 23 is braked by the driver 43 that is turned on and off and the brake release detecting means 41.CancelAn assisting control means 44 comprising a microcomputer that switches the driver 43 on when it is detected that it is stepped on and switches off the driver 43 when it is not detected is provided.
[0050]
  As shown in FIG. 3, in this embodiment, the brake release detecting means 41 is constituted by a micro switch, and the brake pedal 23 is braked.CancelWhen in the position, for example, it is released from the driving piece 45 fixed to the bell crank 35 and turned on, and the brake pedal 32 is braked.CancelWhen rotating from the position in the brake acting direction, it is driven by the driving piece 45 to be turned off.
[0051]
  When the brake release detecting means 41 is turned on, the assisting control means 44 switches the driver 43 on to energize the biasing means 42. When the brake release detecting means 41 is turned off, the assisting control means 44 44 switches off the driver 43 to cut off the drive current of the biasing means 42.
[0052]
  The biasing means 42 is supported by the support frame 2g, and the front end portion of the brake pedal 23 is fixed to the rotating shaft 42a. As a result, the brake pedal 23 is braked together with the rotary shaft 42a around the rotary shaft 42a.CancelIt is supported by the support frame 2g so that it can rotate between the position and the maximum braking action position.
[0053]
  FIG. 6 is a cross-sectional view schematically showing the structure of a rotary solenoid constituting the urging means 42. The urging means 42 includes a casing 42b fixed to the support frame 2g and the casing 42b. A rotor 42c that is rotatably supported within a predetermined angle range within the casing 42b via a shaft 42a, and an electromagnet 42d that magnetically attracts the rotor 42c to one end side of the rotation stroke are provided. When the energizing means 42 is energized, the rotor 42c is attracted by the electromagnet 42d in the direction opposite to the energizing force of the spring 30 to energize the brake pedal 23, and when not energized, the rotor 42c is electromagnet 42c. Thus, the brake pedal 23 can be freely rotated within a predetermined range together with the rotating shaft 42a. Thus, the brake pedal 23 is brakedCancelWhen the brake pedal 23 is energized in the depression direction by the assisting means 40 when positioned at the position, the operation force that the operator continues to depress the brake pedal 23 can be reduced by this energizing force, and the labor load of the operator is correspondingly increased. It is reduced.
[0054]
  Even if the operator is weak, such as an elderly person, a woman, or a person with a physical disability, the brake pedal 23 is braked.CancelIt becomes easier to keep stepping on the position.
[0055]
  By the way, as shown in FIG.Helping means 40However, an accelerator operation detecting means 46 for detecting that the accelerator operating tool 14 is operated, that is, tilted forward or backward from the neutral position is provided. The accelerator operation detecting means 46 is driven by the accelerator operation tool 14 and turned on, for example, when the accelerator operation tool 14 is positioned at a neutral position so that it can detect that the accelerator operation tool 14 is operated. When the accelerator operating tool 14 is located at a position other than the neutral position, the accelerator operating tool 14 is released from the accelerator operating tool 14 and is turned off. When the accelerator operation detection means 46 is on, the assist control means 44 and the brake release detection means 41 are connected to the power source 47 so that the assist means 40 can be operated. In other words, the brake pedal 23 is braked during the accelerator operation.CancelWhen stepped on, the assisting means 40 is activated and the brake pedal 23 is biased in the stepping direction. On the other hand, when the accelerator operation detecting means 46 is off, the assist control means 44 is disconnected from the power source 47 to invalidate it, and the brake release detecting means 41 is disconnected from the power source 47 so that the assist means 40 It becomes impossible to operate. This eliminates the resistance of the assisting means 40 with respect to the operation of the brake pedal 23 during coasting, facilitates delicate brake operation, and reduces wasteful power consumption.
[0056]
  In this example,The assist control means 44 is constituted by a microcomputer. Instead of this, for example, as shown in the electric circuit diagram of FIG. 7, a switch circuit interposed in a power supply circuit for supplying power to the urging means 42. The assist control means 44 may be configured as described above.
[0057]
  The assisting means 44 composed of this switch circuit is such that the brake release detecting means 41 and the accelerator operation detecting means 46 are interposed in series, but a relay coil interposed in the power supply circuit of the brake release detecting means 41 is provided. The release switch provided and the release switch having a relay coil interposed in the power supply circuit of the accelerator operation detection means 46 may be interposed in series in the power supply circuit of the biasing means 42.
[0058]
  FIG. 8 is a side view of a braking device for a lift truck according to another embodiment of the present invention. As shown in FIG. 8, in this embodiment, the biasing means 42 is an intermediate height of the first rod 34. Now, it is supported by the connecting plate 2f.
[0059]
  Then, when the brake pedal 23 is depressed to the brake release position, a rack tooth row 42e is formed at an intermediate height portion of the first rod 34 that moves toward the connecting plate 2f so as to face the connecting plate 2f. A gear 42f to be engaged with and disengaged from the rack tooth row 42e is fixed to the rotating shaft 42a of the biasing means 42. In this embodiment, when the brake pedal 23 is stepped on to the brake release position, the rack tooth row 42e moves to the connecting plate 2g side and meshes with the gear 42f. The pedal 23 is urged in the depression direction via the first rod 34.
[0060]
  In contrast, the brake pedal 23 is braked.CancelWhen moving from the position to the brake acting side, the rack tooth row 42e is separated from the gear 42f, and the urging means 42 cannot urge the brake pedal 23 in the depression direction.
[0061]
  In this exampleAlsoBrake pedal 23 is braked during accelerator operation as in the previous exampleCancelSince the urging means 42 is energized only when it is positioned, useless power consumption can be reduced.
[0062]
  Other configurations, operations, and effects of this embodiment are the same as those of the previous example.
[0063]
【The invention's effect】
  As described above, according to the present invention, there is provided assisting means for urging the brake pedal in the depression direction when the brake pedal is depressed to the brake release position, so that the brake pedal is depressed to the brake release position. If rare, aboveHelping meansBecause the urging force of this counteracts a part of the elasticity of the spring that urges the brake pedal in the braking action direction, the action required for the operator to keep stepping on the brake pedal to the brake release position is reduced. As a result, the operator's labor load is reduced, and the brake pedal can be braked even by operators with weak braking force, such as elderly people, women, and physically disabled peopleCancelThe effect that it becomes easy to continue stepping on the position is obtained.
[0064]
  Further, when the brake pedal is depressed and the urging means is operated only when the accelerator means is operated and the brake pedal is urged in the depression direction, the urging means is always operated when the accelerator means is operated. Compared with this, wasteful energy consumption can be reduced. Further, when the brake release detecting means detects that the brake pedal is depressed to the brake release position, but the accelerator operation detecting means detects that the accelerator means is not operated, the brake pedal by the biasing means Since the urging in the stepping direction is not performed, the resistance from the assisting means is eliminated during the brake operation when the vehicle travels with inertia and stops, and the delicate brake operation is facilitated.
[Brief description of the drawings]
FIG. 1 is a circuit block diagram of the present invention.
FIG. 2 is a perspective view of the present invention.
FIG. 3 is a side view of the present invention.
FIG. 4 is a rear view of the present invention.
FIG. 5 is a plan view of the present invention.
FIG. 6 is a cross-sectional view of the present invention.
FIG. 7 is an electric circuit diagram of the present invention.
FIG. 8 is a side view of the present invention.
[Explanation of symbols]
8 cab
14 Accelerator operation tool
23 Brake pedal
40 Helping means
41 Brake release detection means
42 Energizing means
44 Auxiliary control means
46 Accelerator operation detection means

Claims (1)

In a braking device for a lift truck provided with a brake pedal provided to perform a brake operation of a deadman system on a cab where an operator gets on,
Brake release detecting means for detecting that the brake pedal is depressed to the brake release position;
Urging means for urging the brake pedal in the depression direction;
An accelerator operation detecting means for detecting the presence or absence of operation of the accelerator means of the lift truck;
When the brake release detecting means detects that the brake pedal is depressed to the brake release position and the accelerator operation detecting means detects that the accelerator means is operated, the urging means is activated. When the brake pedal is not depressed to the brake release position, or the brake release detection means detects that the brake pedal is depressed to the brake release position. Assist means comprising: an assist control means for preventing the urging means from urging the brake pedal in the depression direction when the accelerator operation detecting means detects that the accelerator means is not operated. A lift truck braking device characterized by the above-mentioned .

Images