JP2013184669A - Security device for industrial vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a security device for an industrial vehicle configured to ensure security function as a security device when a seating state detection switch does not normally detect a seating state, and to enable temporary moving or cargo handling operation.SOLUTION: A security device of an industrial vehicle includes: a seating state detection switch 3 for detecting whether a driver has been seated on a driver's seat 2 by contact connection; a control device that cuts off power to be supplied to a solenoid valve for a cargo-handling device that controls supply of operating oil to a forward-travel solenoid valve, a backward-travel solenoid valve, and a hydraulic cylinder of the cargo-handling device to disable the moving and cargo handling operation when non-seating state is detected by the seating state detection switch 3; and an automatic-return push-button release switch 13 which is connected in parallel to the seating state detection switch 3 and performs contact connection only when pushed. The release switch 13 is arranged in a position lower than a seating surface 2a of the seat.

Description

  More particularly, the present invention relates to a safety device including a seat seating detection switch (deadman switch) that detects whether a driver is seated on a seat.

  A conventional safety device will be described with reference to the control circuit diagram of FIG. 4 and the control flowchart of FIG. If the driver's key switch 1 is ON and the driver is seated on the seat 2, the seat seating detection switch 3 having a normally open contact built in the seat portion of the seat 2 is turned ON. 4 is determined to be normal, and traveling and cargo handling operations are possible (S1 → S9, S10, S11).

  When the driver leaves the seat 2, the seat seating detection switch 3 is turned OFF, and if the OFF state is continued for a set time or longer, the control device 4 determines that an abnormality has occurred (S1 → S2 → S3 → S4) and moves forward. The first shut-off relay 8 and the second shut-off relay 9 shut off the energization of the solenoid valve 5 for reverse, the solenoid valve 6 for reverse travel, and the solenoid valve 7 for cargo handling device. Therefore, when the driver is not seated on the seat 2, a safety function that disables traveling and cargo handling operation is activated (S6). At this time, the control device 4 sounds an alarm buzzer 10 that audibly informs that there is an abnormality, and lights a non-seating warning lamp 11 that visually informs that the abnormality is present (S5).

  After energizing the forward solenoid valve 5, the reverse solenoid valve 6, and the cargo handling device solenoid valve 7, the driver is seated again and the seat seating detection switch 3 is turned on to detect seating. The non-seating warning light 11 is turned off and the alarm buzzer 10 is turned off (S8), the energization of the solenoid valve 7 for the cargo handling device is restored to enable the cargo handling operation (S9), and the shift lever (F / R lever) ) Is in the neutral position (S10), the energization of the forward solenoid valve 5 and the reverse solenoid valve 6 is restored to enable forward / reverse travel (S11). Before enabling the forward / reverse running, it is determined in step S10 whether or not it is in the neutral position. When the shift lever is in the forward position or the reverse position, it is prevented that the power is suddenly turned on and suddenly started. It is to do.

  The forward solenoid valve 5 and the reverse solenoid valve 6 are solenoid valves for supplying hydraulic pressure for switching the hydraulic clutch to the forward clutch or the reverse clutch, respectively. A forward switch, a neutral position, and a reverse position are detected by a shift switch 12 that detects an input direction of a shift lever (not shown), and the forward solenoid valve 5 or the reverse solenoid valve 6 is energized according to the shift position. In the neutral position, the forward solenoid valve 5 and the reverse solenoid valve 6 are not energized. Accordingly, when the energization of the forward solenoid valve 5 and the reverse solenoid valve 6 is interrupted, the hydraulic clutch becomes neutral and the vehicle cannot travel.

  The solenoid valve 7 for the cargo handling device is a solenoid valve that controls the hydraulic pressure supplied to the hydraulic cylinder that drives the cargo handling device such as a fork. The drive hydraulic cylinder cannot be operated, and the cargo handling operation becomes impossible.

  As this type of safety device, for example, there are those disclosed in Patent Documents 1 and 2.

JP 2006-316842 A Japanese Utility Model Publication 2-51934

  In general, the seat contact detection switch changes the connection state of the internal contact between the seating state and the non-sitting state, and the input from the seat seating detection switch to the control device changes due to the change. Determine whether normal or non-seated (abnormal).

  Therefore, if the seating signal is not sent to the control device due to a failure due to a contact failure of the seat seating detection switch or a failure such as disconnection of the electrical wiring connecting the seat seating detection switch and the control device, In spite of this, the control device judges that it is not seated (abnormal) and disables traveling and disables the cargo handling operation.

  However, if such a situation occurs, for example, on the road, the vehicle cannot be moved, and in particular in the case of a large industrial vehicle, it is not easy to tow. Also, if the cargo handling device stops at the high head position with cargo or the like placed on it, unloading becomes difficult.

  Therefore, in order to solve the above problems, the present invention temporarily travels while ensuring a safety function as a safety device when a malfunction occurs in which the seat seating detection switch does not normally detect seating. The main object of the present invention is to provide a safety device for an industrial vehicle that enables a cargo handling operation.

  In order to achieve the above object, a safety device for an industrial vehicle according to the present invention includes, as a first means, a seat seating detection switch for detecting presence / absence of seating by connecting contacts when seating a driver's seat, and the seat When the non-seating is detected by the seating detection switch, a control device that cuts off power to the forward solenoid valve and the reverse solenoid valve and disables traveling, and the seat seating detection switch are connected in parallel and pressed. And an automatic return type push button type release switch that connects contacts only between the two, and the release switch is disposed at a position lower than the seating surface of the seat.

  The industrial vehicle safety device according to the present invention includes, as a second means, a seat seating detection switch for detecting presence / absence of seating by connecting a contact when a driver's seat is seated, and the seat seating detection switch. When non-sitting is detected, the solenoid valve for forward movement, the solenoid valve for backward movement, and the solenoid valve for cargo handling device that controls the supply of hydraulic oil to the hydraulic cylinder of the cargo handling device are cut off to perform traveling and cargo handling operations. A control device for disabling, and an automatic return type push button type release switch that is connected in parallel to the seat seating detection switch and is connected to a contact point only while it is being pushed, and the release switch is a seating surface of the seat It is placed at a lower position.

  In the first or second means, the release switch is preferably attached to the seat.

  In the first or second means, the release switch may be attached to a front guard.

  According to the present invention, even if a safety device that makes it impossible to run or unload even though it is seated on the seat due to a malfunction such as a failure of the seat seating detection switch, the safety device is temporarily suspended by the release switch. Can be released automatically. And since the release switch is an automatic return type push button type switch, it is necessary to keep pressing the release switch to release the safety device, and the fingertip of one hand is required. However, it is possible to provide an obstacle to the continuation of the normal work in a state where the defect is left without being repaired. Furthermore, the operator pushes the release switch while operating the steering handle or the lever of the cargo handling device, but operates the steering handle or the lever of the cargo handling device that is higher than the seating surface of the seat with one hand. However, since it is necessary to operate the release switch at a position lower than the seating surface of the seat with the other hand, one hand is restrained at a position higher than the seating surface of the seat, and the position is lower than the seating surface of the seat. The other hand is restrained, and as a result, if the operator tries to operate the steering handle or the operating lever and push the release switch at the same time, the operator will inevitably be near the seating surface of the seat in the middle position of both hands. The position of the operator's buttocks will be constrained, the seating posture will be taken, and the seating posture will be maintained even when the safety device is temporarily released by the release switch By the so that it is possible to ensure the safety function of the safety device.

FIG. 1 is a control circuit diagram of an embodiment of a safety device for an industrial vehicle according to the present invention. 2 is a partially cutaway side view around the driver's seat showing an example of the arrangement of the release switch of the control circuit of FIG. FIG. 3 is a partially cutaway side view around the driver's seat showing another arrangement example of the release switch of the control circuit of FIG. FIG. 4 is a control circuit diagram of a conventional industrial vehicle safety device. FIG. 5 is a control flowchart of the control device arranged in the control circuit of FIG.

  An embodiment of an industrial vehicle safety device according to the present invention will be described below with reference to FIGS. FIG. 1 is a control circuit diagram showing an embodiment of a safety device for an industrial vehicle according to the present invention. Throughout the drawings, the same reference numerals are assigned to the same components including the prior art. The control device shown in FIG. 1 has the same control flow as the conventional control flow shown in FIG.

  The embodiment of the present invention shown in FIG. 1 differs from the circuit configuration of the conventional safety device shown in FIG. 4 in that the release switch 13 is connected in parallel to the seat seating detection switch 3. Are the same. The release switch 13 is an automatic return type push button switch, and is a normally open contact (a contact) that is contact-connected only while being pressed.

  Since the release switch 13 is connected in parallel to the seat seating detection switch 3, the terminal input to the control device 4 is the same as in the case of contact connection by seating of the seat seating detection switch 3 while the release switch 13 is being pressed. Even if the seat seating detection switch 3 is in an OFF state (contact non-connecting state) corresponding to a non-sitting state due to a failure due to a malfunction, the control device 4 is in a seating state, that is, a seat seating detection switch. 3 is recognized as being ON (contact connection state).

  Therefore, when the seat seating detection switch 3 erroneously detects that the seat is not seated due to a contact failure or the like despite being seated, the control device 4 uses the first cutoff relay 8 and the second cutoff relay 9 to advance. Even if the solenoid valve 5, the reverse solenoid valve 6 and the solenoid valve 7 for cargo handling device are de-energized to disable running and cargo handling operation (see S <b> 1 to S <b> 6 in FIG. 5), the release switch 13 is pressed. While the release switch 13 is being pressed, the control device 4 recognizes (determines) that the seating state has been reached again.

  Then, when the control device 4 determines that the seating is performed while the release switch 13 is being pressed, the control device 4 enables the handling operation by controlling the second cutoff relay 9 to return the energization to the solenoid valve for the cargo handling device, Further, if it is detected as an additional condition that the shift switch 12 is in the neutral position, the first cut-off relay 8 is controlled to return the energization to the forward solenoid valve 5 and the reverse solenoid valve 6 to enable traveling. (Refer to S7 to S11 in FIG. 5).

  The release switch 13 enables the safety device to be temporarily released when the safety device malfunctions due to a failure of the seat seating detection switch 3. Therefore, it is necessary that the operator does not release the safety device by operating the release switch 13 even though the seat seating detection switch 3 has not failed. For example, in a forklift, it is possible to operate the release switch while looking into the driver's cab in order to check the state of cargo or the like mounted on the fork in front of the driver's seat when the operator is away from the seat 2. If this is the case, it may be dangerous that a part of the operator's body accidentally touches the tilt lever and the mast is tilted (tilted).

  In order to avoid the above risk, the release switch 13 is disposed at a position lower than the seating surface 2a of the seat 2 as shown in FIGS. When the release switch 13 is at a position lower than the seating surface 2 a of the seat 2, the operator cannot take a posture of riding forward from the cab while the release switch 13 is being pressed.

  Further, since the operator presses the release switch 13 while operating the operating lever 15 of the steering handle 14 or a cargo handling device (not shown) such as a fork, the steering at a position higher than the seating surface 2 a of the seat 2. It is necessary to operate the handle 14 or the operation lever 15 of the cargo handling device with one hand, and operate the release switch 13 at a position lower than the seating surface 2a of the seat 2 with the other hand. That is, one hand is restrained at a position higher than the seating surface 2 a of the seat 2, and the other hand is restrained at a position lower than the seating surface 2 a of the seat 2. As a result, if the operator tries to operate the steering handle 14 or the operating lever 15 and push the release switch 13 at the same time, the operator inevitably comes near the seating surface 2a of the seat 2 in the middle position of both hands. The position of the buttocks is restrained and the seating posture is taken. Thus, even when the safety device is temporarily released by the release switch 13, the safety function of the safety device can be ensured by maintaining the sitting posture.

  The release switch 13 can be attached to the seat 2. In the example of FIG. 2, the release switch 13 is supported near the side surface so as to protrude from the side surface of the seat 2 via a bracket (not shown) fixed to the seat 2. ing. The release switch 13 may be arranged so as to be hidden behind the seating surface of the seat 2, or may be fixed or embedded on the side surface of the seat 2. As shown in FIG. 2, the release switch 13 is preferably arranged so that the push button faces downward so that it is not touched during normal times.

  In the example of FIG. 3, the release switch 13 is disposed on the driver seat side of the driver seat front guard 16. When the operation lever 15 of the cargo handling device is disposed on the right side toward the steering handle 14, in consideration of operability, the release switch 13 is seated near the left knee toward the steering handle 14. Although it may be arranged at an operable position, it may be arranged just below the steering handle 14. When the release switch 13 is attached to the front guard 16, as shown in FIG. 3, the release switch 13 is fixed to the inside of the side plate 16b facing the driver's seat via a bracket or the like so as to be hidden under the top plate 16a of the front guard 16. At the same time, it is preferable that the push button be arranged downward.

  The present invention is not limited to the embodiment described above, and can be modified without departing from the spirit of the present invention.

  For example, in the above-described embodiment, the energization of the forward solenoid valve 5, the reverse solenoid valve 6, and the cargo handling device solenoid valve 7 is restored. However, in an industrial vehicle that does not include the cargo handling device solenoid valve such as a towing vehicle. Only the solenoid valves 5 and 6 for forward / reverse movement can be configured to return to energization.

  In addition, in order to detect the seating, the detection switch built in the seat portion of the seat is exemplified as the seat seating detection switch. However, a switch for detecting that the seat belt is attached is further provided. It can be determined that the user is seated when the switch is ON.

2 Seat 2a Seating surface 3 Seat seating detection switch 4 Control device 5 Forward solenoid valve 6 Backward solenoid valve 7 Cargo handling device solenoid valve 13 Release switch 16 Front guard

Claims (4)

A seat seating detection switch for detecting presence / absence of seating by connecting a contact when seating a driver's seat;
A control device that shuts off the energization to the forward solenoid valve and the reverse solenoid valve when the non-seating is detected by the seat seating detection switch;
An automatic return type push button type release switch that is connected in parallel to the seat seating detection switch and is connected to the contact point only while it is being pressed;
The safety device for an industrial vehicle, wherein the release switch is disposed at a position lower than a seating surface of the seat. A seat seating detection switch for detecting presence / absence of seating by connecting a contact when seating a driver's seat;
When non-seating is detected by the seat seating detection switch, the energization of the forward solenoid valve, the reverse solenoid valve, and the cargo handling device solenoid valve that controls the supply of hydraulic oil to the hydraulic cylinder of the cargo handling device is cut off. And a control device that disables traveling and cargo handling operations,
An automatic return type push button type release switch that is connected in parallel to the seat seating detection switch and is connected to the contact point only while it is being pressed;
The safety device for an industrial vehicle, wherein the release switch is disposed at a position lower than a seating surface of the seat.   The industrial vehicle safety device according to claim 1, wherein the release switch is attached to the seat. The industrial vehicle safety device according to claim 1, wherein the release switch is attached to a front guard.

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