JPH0549793U - Lift detection device for forklift - Google Patents

Abstract

(57) [Summary] [Purpose] To detect the lift of a fork with a device that is easy to assemble. [Structure] A pair of limit switches LS1 and LS2 are fixed to a mast 5A standing upright in front of the vehicle body at a predetermined interval, and a boat-shaped touch piece 11 having a length shorter than the arrangement interval of the pair of limit switches is fixed. When the self-holding circuit is incorporated in the control circuit so that the limit switch LS1 located below the pair of limit switches and the normally closed contact of the self-holding relay are connected in series, the short touch piece The fork lift height can be detected, the number of assembling steps is simplified, the appearance is good, and the front weight of the forklift is reduced.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention is a lift detection device for a forklift, which is used for control of turning on a rotating lamp when the fork height exceeds a predetermined height, and is intended for easy assembly.

[0002]

[Prior Art]

 Conventionally, when it is used for control that the rotating lamp lights when the fork height exceeds a predetermined height, a limit switch is fixed to the mast, and when the fork height exceeds the predetermined height together with the mast, the mast is A touch piece having a length capable of maintaining a state where it is always in contact with the limit switch is provided, and the touch piece comes into contact with the limit switch, and the limit switch operates to detect a predetermined height.

[0003]

[Problems to be solved by the device]

 In the conventional technology as described above, a touch piece having a length that can maintain the state of being in constant contact with the limit switch must be provided, so that the mounting position can be limited, and the appearance is not good. The weight of the vehicle was bulky, and the task of violating the proposition of reducing the weight distribution in front of the forklift was created. The present invention has been devised to solve the above problems.

[0004]

[Means for Solving the Problems]

 The present invention relates to a forklift in which a mast is erected in front of a vehicle body and a fork that moves up and down the mast is locked, and a pair of limit switches is provided at a predetermined distance downward from the upper end of the outer mast of the mast. The upper part of the inner mast of the mast, and a boat-shaped touch piece having a length shorter than the arrangement interval of the pair of limit switches at a predetermined distance from the lower end of the inner mast. The limit switch located below the switch and the normally-closed contact of the self-holding relay are connected in series, or a pair of limit switches are fixed at a fixed interval from the upper end of the inner mast to lower the inner mast. One side of the moving lift bracket has a boat shape with a length shorter than the interval between the pair of limit switches. A structure for fixing the touch piece, and solve the above problem.

[0005]

【Example】

 An embodiment of the present invention will be described with reference to FIGS. 1, 2, 3 and 4. FIG. 1 is a side view of a counter type lift truck equipped with the present invention. 1 is a counter type lift truck, 2 is the body of the counter type lift truck 1, 3 is a drive wheel, 4 is a free wheel, 5 is a mast, and the mast 5 is an outer mast 5A and an inner mast 5B. 6 is a lift bracket that moves the inner mast 5B up and down, 7 is a pair of forks that are locked to the lift bracket 6, 8 is an outer mast 5A, or a limit switch group fixed to the inner mast 5B, and 9 is the limit switch. The control device 10 for performing a predetermined control by the operation signal from the switch group 10 is a rotating light or a buzzer which is operated by the output signal from the control device 9, and is a rotating light in this example.

FIG. 2 is a side view showing a mounted state of the limit switch group. In the limit switch group, two limit switches LS1 and LS2 are arranged at a predetermined interval, and the inner mast 5B or the lift bracket is arranged. The touch piece 11 fixed on one side of the switch 6 moves from the limit switch LS1 to the limit switch LS2 when the fork 7 moves up, and from the limit switch LS2 to the limit switch LS1 when the fork 7 moves down. The contacts are sequentially made to operate the limit switch L S1 and the limit switch LS2.

FIG. 3 shows a control circuit in which the exciting coil x1 of the self-holding relay, the normally closed contact NC of the limit switch LS1 and the normally open contact NO of the limit switch LS2 are connected in series. The normally open contact X1 of is connected in parallel to the normally open contact NO of the limit switch LS2. Further, the rotating-light motor MR and the normally-open contact X2 of the self-holding relay are connected in series.

FIG. 4 is a time chart. The operation will be described based on the time chart. When the fork 7 rises, the touch piece 11 fixed to one side of the inner mast 5B or the lift bracket 6 also rises. Then, the touch piece 11 operates the limit switch LS1 to open the normally closed contact NC of the limit switch LS1, and when the touch piece 11 further rises, the touch piece 11 stops the operation of the limit switch LS1 and then the touch piece 11 When the limit switch LS2 is operated, current flows through the exciting coil x1 of the self-holding relay, the normally closed contact NC and the normally open contact X1 of the self-holding relay, and the normally-open contact X2 of the self-holding relay and the rotating lamp. A current flows through the motor for motor MR and the rotary lamp 10 moves. Even if the touch piece 11 further rises and the operation of the limit switch LS2 is stopped, the self-holding circuit is formed, so that the current flows to the normally-open contact X2 of the self-holding relay and the rotating lamp motor MR. , Revolving light 10 is still moving.

When the fork 7 descends, the touch piece 11 fixed to one side surface of the inner mast 5B or the lift bracket 6 also descends, and the touch piece 11 self-holds even if the limit switch LS2 is operated. Since the circuit is formed, current flows through the normally-open contact X2 of the self-holding relay and the rotating lamp motor MR, and the rotating lamp continues to move. However, when the touch piece 11 is further lowered and the limit switch L S1 is operated, the normally closed contact NC is opened, the current is cut off, and the rotary lamp motor MR is stopped.

[0010]

【effect】

 As described above, according to the present invention, when the self-holding circuit is incorporated in the control circuit, the lift amount of the forklift can be detected by the short touch piece, the assembling man-hours are simple, and the appearance is good. It is also effective for mitigation.

[Brief description of drawings]

FIG. 1 is a side view of a counter-type forklift equipped with the present invention.

FIG. 2 is a side view showing a mounted state of a limit switch group.

FIG. 3 is a control circuit.

FIG. 4 is a time chart.

[Explanation of symbols]

 1 counter type lift truck 2 vehicle body 3 drive wheel 4 idler wheel 5 mast 6 lift bracket 7 fork 8 limit switch group 9 controller 10 revolving light 11 touch piece

Claims (2)

[Scope of utility model registration request] 1. A forklift in which a mast is erected in front of a vehicle body and a fork for moving the mast up and down is locked, and a pair of limits are provided downward from the upper end of the outer mast of the mast at a predetermined interval. The switch is fixed, and a boat-shaped touch piece having a length shorter than the arrangement interval of the pair of limit switches is fixed at a predetermined interval from the lower end of the inner mast in the mast, and the pair of limit switches Lift detection device for forklift trucks, which is composed of a limit switch located in the lower part of the inside of the vehicle and a normally closed contact of a self-holding relay connected in series. 2. A forklift in which a mast is erected in front of a vehicle body and a fork that moves up and down the mast is locked, and a pair of limits are provided downward from the upper end of the inner mast of the mast at a predetermined interval. The switch is fixed, and a boat-shaped touch piece having a length shorter than the arrangement interval of the pair of limit switches is fixed to one side of the lift bracket that vertically moves the inner mast, and the lower part of the pair of limit switches is fixed. Lift detection device for forklift trucks in which the limit switch located and the normally closed contact of the self-holding relay are connected in series.