JPH066396U - Mast device - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent the noise caused by the floating body. An elevating prevention means 7 is provided between the elevating body 4 and the moving mast 3 to prevent the relative elevating and lowering of these, and an elevating operation means 6 for controlling the elevating and lowering drive means 5 is connected to the elevating and lowering means via a connecting means 8. Make 7 operate.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement of a mast device applied to a cargo handling vehicle such as a forklift truck.

[0002]

[Prior art]

 Conventionally, as the mast device of this type, those described in, for example, Japanese Utility Model Publication No. 52-7627 and Japanese Utility Model Publication No. 52-7628 are known. These are basically a fixed mast, a moving mast that can be moved up and down on the fixed mast, an elevating body that can be moved up and down on the moving mast, and a moving mast that moves up and down with respect to the fixed mast. Elevator drive means for raising and lowering the elevating body with respect to the moving mast, elevating operation body for controlling the elevating drive means, and a fixed mast that prevents the elevating body from descending relative to the fixed mast. It is composed of a descent blocking means operable from a blocking state to a descent state allowing these relative ascent and descent, and an operating body for controlling the descent blocking means. However, in such a device, since the descent blocking means for blocking only the lowering of the lifting body with respect to the fixed mast is provided between the fixed mast and the lifting body, only the descent can be blocked at a predetermined position. There wasn't. For this reason, when such a mast device is mounted on a cargo handling vehicle, for example, when traveling on a rough road with no load, the ascending / descending body jumps up due to the unevenness of the road surface, or the chain of the ascending / descending driving means jumps. However, there was a problem in that noise was generated.

[0003]

[Problems to be solved by the device]

 The present invention was devised in order to solve this problem in view of the above problems, and the purpose thereof is to provide a mast device which prevents noise due to the floating motion of the lifting body. is there.

[0004]

[MEANS FOR SOLVING THE PROBLEMS] A mast device of the present invention includes a fixed mast, a movable mast that is vertically movable on the fixed mast, an elevating body that is vertically movable on the movable mast, and a fixed mast. On the other hand, the elevating and lowering drive means for elevating and lowering the moving mast and the elevating and lowering body with respect to the moving mast, the elevating and lowering operation body for controlling the elevating and lowering drive means, and the relative movements provided between the elevating body and the moving mast. Lifting prevention means that can operate from a blocking state that prevents lifting up and down to an allowable state that allows these relative lifting, and a lifting blocking means that is provided between the lifting operation body and the movement blocking means when the lifting operation body is in neutral. It is characterized in that it is composed of a connecting means for bringing the up-and-down prevention means into the permissible state when the up-and-down operation body is operated.

[0005]

[Action]

 When the lifting operation body is neutral, the operation of the lifting drive means is stopped, and the lifting of the moving mast with respect to the fixed mast and the lifting of the lifting body with respect to the moving mast are stopped. At this time, the ascending / descending blocking means is brought into the blocked state via the connecting means, and the lifting / lowering of the lifting / lowering body with respect to the moving mast is blocked. Therefore, noise due to this can be prevented. During operation of the lifting / lowering operation body, the lifting / lowering drive means is operated to raise / lower the moving mast with respect to the fixed mast, and also raise / lower the lifting / lowering body with respect to the moving mast. At this time, the ascending / descending blocking means is brought into the permitted state through the connecting means, and the ascending / descending body is allowed to ascend / descend with respect to the moving mast.

[0006]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic view showing a mast device according to an embodiment of the present invention. The main part of the mast device 1 is composed of a fixed mast 2, a movable mast 3, a lifting body 4, a lifting drive means 5, a lifting operation body 6, a lifting prevention means 7, and a connecting means 8. The fixed mast 2 forms a basic part of the mast device 1, and in this example, a lower portion of a vehicle body (not shown) of a forklift is attached so as to be able to tilt forward and backward. A tilt cylinder (not shown) that tilts the fixed mast 2 back and forth is interposed between the fixed mast 2 and the vehicle body. The movable mast 3 is provided on the fixed mast 2 so as to be movable up and down, and in this example, is provided with a stopper 9. Between the moving mast 3 and the fixed mast 2, an end roller and a side roller (neither of which is shown) for smoothly moving up and down the moving mast 3 are arranged. The elevating body 4 is provided on the moving mast 3 so as to be able to move up and down, and in this example, is provided with a lift bracket 10, a finger bar 11, and a fork 12. An end roller 13 and a side roller (not shown) are provided between the lift bracket 10 of the lifting body 4 and the moving mast 3 to smoothly lift the lifting body 4. The elevating and lowering drive means 4 elevates and lowers the moving mast 3 with respect to the fixed mast 2 and the elevating and lowering body 4 with respect to the moving mast 3. A single-acting lift cylinder 14 having a predetermined free lift space formed between it and the stopper 9, a sheave 15 rotatably provided around the horizontal axis on the rod-side upper portion of the lift cylinder 14, and a fixed mast at one end. 2 is provided with a chain 16 having the other end fastened to the lift bracket 10 of the lifting body 4 and halfway over the sheave 15. The raising / lowering operation body 6 controls the raising / lowering drive means 5, and in this example, is an operation lever of a manual lift control valve 17 for controlling the lift cylinder 14. The lift control valve 17 is a six-port three-position switching valve. The primary side first port is to the pump 18, the primary side second port is to the pump 18 via the check valve 19, and the primary side third port is. In the tank 20, the secondary side second port is connected to the tail chamber of the lift cylinder 14, and the secondary side third port is blind. The up-and-down prevention means 6 is provided between the moving mast 3 and the up-and-down body 4 and is operable from a blocking state for blocking the relative up-and-down movement of these to a permissible state for permitting these relative up-and-down movements. In this example, A lock cylinder 21 provided on the lift bracket 10 of the lifting body 4, an engagement body 22 provided on the rod side of the elevation cylinder 4 to engage with the flange of the movable mast 3, and an engagement body provided on the rod chamber of the lock cylinder 21. 22 is a hydraulic type composed of a spring 23 for separating the flange 22 of the movable mast 3 from each other, and the lock cylinder 21 and the spring 23 form a spring-return type single-acting cylinder. The connecting means 8 is provided between the raising / lowering operation body 6 and the raising / lowering prevention means 7, and when the raising / lowering operation body 6 is in a neutral state, the raising / lowering prevention means 7 is in a blocking state, and when the raising / lowering operation body 6 is operated, the raising / lowering prevention means 7 is provided. In this example, the manual lock control valve 24 is mechanically connected to the operation lever of the lift control valve 17 to control the lock cylinder 21 of the lifting / lowering prevention means 7. The lock control valve 24 is a six-port three-position switching valve. The primary side first port is the secondary side first port of the lift control valve 17, and the primary side second port is the lift control via the check valve 25. The secondary side first port of the valve 17, the primary side third port and the secondary side first port are connected to the tank 20, and the secondary side second port is connected to the tail chamber of the lock cylinder 21, respectively. The three ports are blind. Next, the operation will be described based on such a configuration. When the operation lever of the lift control valve 17 that forms the lifting operation body 6 is in the neutral position, the lift control valve 17 is in the center neutral position in FIG. 1, the operation of the lift cylinder 14 that forms the lifting drive means 5 is stopped, and the fixed mast 2 The lifting of the moving mast 3 with respect to the moving mast 3 and the lifting of the lifting body 4 with respect to the moving mast 3 are stopped. At this time, the lock control valve 24 forming the connecting means 8 is in the central supply position in FIG. 1, and the pressure oil from the pump 18 is sent to the tail chamber of the lock cylinder 21 forming the up-and-down prevention means 7, which is sprinkled. It is extended against the guide 23, the fitting 22 is fitted to the flange of the moving mast 3, and the ascending / descending preventing means 7 is set in the blocking state, so that the lifting / lowering body 4 is prevented from moving up and down with respect to the moving mast 3. Therefore, noise due to this is prevented. When operating the operating lever of the lift control valve 17 that forms the lifting operation body 6, the lift control valve 17 is in the ascending or descending position on the right or left side in FIG. 1, and the lift cylinder 14 that constitutes the ascending / descending drive means 5 is extended or shortened. The moving mast 3 is moved up and down with respect to the fixed mast 2, and the lift 4 is moved up and down with respect to the moving mast 3. At this time, the lock control valve 24 forming the connecting means 8 is in the discharge position on the right side or the left side in FIG. 1, and the pressure oil in the tail chamber of the lock cylinder 21 forming the lifting / lowering prevention means 7 is circulated to the tank 20 to cause the spring 23. The moving body 22 is separated from the flange of the moving mast 3 to bring the up-and-down prevention means 7 into an allowable state, and the moving body 3 is allowed to move up and down.

Although the lifting drive means 5 is capable of so-called free lift in the previous embodiment, the lift drive means 5 is not limited to this, and may be, for example, one that cannot be free lifted. Although the raising / lowering operation body 6 is the operation lever of the lift control valve 17 in the above-mentioned embodiment, it is not limited to this and may be, for example, an electric switch or the like. In the previous embodiment, the lifting / lowering preventing means 7 was a so-called hydraulic type composed of the lock cylinder 21, the mating body 22 and the spring 23, but is not limited to this, and may be, for example, a mechanical type or an electric type. In the above embodiment, the connecting means 8 is the manual lock control valve 24 mechanically connected to the lifting operation body 6, but the connection means 8 is not limited to this. For example, an electric switch operated by the lifting operation body 6 may be used. It is provided to electrically connect this to the electromagnetic lock control valve 24, or to make the lifting operation body 6 an electric switch, and to electrically move the lift control valve 17 and the lock control valve 24 to electrically connect them. If the up-and-down prevention means 7 is mechanical, it is connected mechanically by using a push-pull cable. If the up-and-down prevention means 7 is electrically operated, it is electrically connected by an electric wire. You may

[0008]

[Effect of device]

 As described above, according to the present invention, the following excellent effects can be obtained. (1) Composed of a fixed mast, a moving mast, an elevating body, an elevating / lowering drive means, an elevating operation body, an elevating and lowering blocking means, and a connecting means, and in particular, an elevating and lowering block for preventing relative elevation of these between the elevating body and the moving mast Since the means is provided, it is possible to prevent the noise caused by the floating body. (2) Since the lifting prevention means is operated via the connecting means depending on the lifting operation body that controls the lifting drive means, the operation body dedicated to the lifting prevention means can be omitted, and the operation is simplified. You can

[Brief description of drawings]

FIG. 1 is a schematic view showing a mast device according to an embodiment of the present invention.

[Explanation of symbols]

1 ... Mast device, 2 ... Fixed mast, 3 ... Moving mast, 4
... Elevating body, 5 ... Elevating drive means, 6 ... Elevating operation body, 7 ... Elevating prevention means, 8 ... Connecting means, 9 ... Stopper, 10 ... Lift bracket, 11 ... Finger bar, 12 ... Fork,
13 ... End roller, 14 ... Lift cylinder, 15 ... Sheave, 16 ... Chain, 17 ... Lift control valve, 18 ... Pump, 19 ... Check valve, 20 ... Tank, 21 ... Lock cylinder, 22 ... Coupling, 23 ... Spring, 24 ... Lock control valve, 25 ... Check valve.

Claims (1)

[Scope of utility model registration request] 1. A fixed mast, a movable mast that can be moved up and down on the fixed mast, an elevating body that can be moved up and down on the movable mast, and a movable mast that moves up and down with respect to the fixed mast. An elevating and lowering drive means for elevating and lowering the elevating and lowering body, and an elevating and lowering operation body for controlling the up and down drive means
Between the lifting and lowering body and the movement blocking means, which is provided between the lifting and lowering body and the movable mast and is operable from a blocking state for blocking the relative lifting and lowering thereof to a permitting state for allowing the relative lifting and lowering thereof A mast device, comprising: a connecting means that is provided in the upper part of the lifting operation body when the lifting operation body is in a neutral state, and that connects the lifting prevention means when the lifting operation body is operated.