JPH071356U - Hydraulic emergency circuit of hydraulic clutch type transmission - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] When the hydraulic pump fails, it is possible to maintain normal running while avoiding the situation where the hydraulic clutch cannot be controlled. A hydraulic emergency circuit is provided so as to prevent the vehicle from running out of control when the valve is in a power failure state due to a failure of the power supply device and stops traveling. [Structure] An emergency switching valve V1 is provided in an oil passage from a hydraulic pump P1 for sending oil to a hydraulic clutch to a hydraulic clutch control circuit, and when the hydraulic pump P1 fails, the emergency switching valve V1 is turned off. By changing the oil pressure, oil can be sent from the other hydraulic pump P2 to the hydraulic clutch, and the oil passage between the high speed forward clutch FH and the high speed forward clutch valve S1 that enters when the pressure oil supply is stopped is safe. Solenoid valve for stop V
The safety emergency stop solenoid valve V2 is switched at the time of a power failure by supplying the pressure oil to the high-speed forward clutch FH, and the hydraulic emergency circuit is configured to disconnect the clutch.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a configuration of an emergency circuit when a hydraulic pump in a hydraulic circuit for controlling a hydraulic clutch of a tractor or the like fails or a power supply device for a solenoid valve fails.

[0002]

[Prior art]

 Conventionally, in a traveling vehicle such as a tractor that operates at low speed, a technique of disposing an auxiliary transmission including a hydraulic clutch between an engine output shaft and an input shaft of a transmission case with a built-in transmission has been disclosed. No. 4-107348. Among them, the hydraulic clutch of the auxiliary transmission is composed of a low speed forward clutch, a reverse clutch, and a high speed forward clutch, and the input shaft of the mission case is driven by low speed forward drive, high speed forward drive, by selectively connecting each clutch. Alternatively, it is driven in reverse, and each clutch switching solenoid valve is provided in the hydraulic circuit to each hydraulic clutch. The solenoid valve is opened in an energized state to supply pressure oil to the hydraulic clutch, and is closed during a power failure to stop the pressure oil supply to the hydraulic clutch. Then, the hydraulic clutch for low speed forward movement and the hydraulic clutch for reverse movement are designed to start when pressure oil is supplied and disengage when pressure oil supply is stopped, while the hydraulic clutch for high speed forward drive disengages when pressure oil is supplied. It is configured to start when the pressure oil supply is stopped.

[0003]

[Problems to be solved by the device]

 In the hydraulic circuit for hydraulic clutch control of the auxiliary transmission as described above, when the hydraulic pump that supplies oil to each hydraulic clutch fails, oil supply to each hydraulic clutch and solenoid valve stops, and the solenoid valve The hydraulic clutch cannot be controlled regardless of whether it is opened or closed. As a result, the hydraulic clutch that enters due to the stop of the pressure oil supply suddenly enters, the vehicle runs out of control, the clutches and shaft members of the traveling system are damaged, and the operator cannot cope with sudden changes in the traveling state. , There is danger.

Further, if the energization of the solenoid valve is stopped due to a failure of the power supply device, each solenoid valve is closed and the pressure oil supply to each hydraulic clutch is stopped. As a result, the hydraulic clutches for low speed forward movement and reverse movement are disengaged, but the hydraulic clutch for high speed forward movement is configured to start when pressure oil is stopped.Therefore, the hydraulic clutch is closed when the solenoid valve is closed. Then, there is a danger that the vehicle will suddenly be driven at a high speed, and the vehicle will run out of control. Further, since the power supply is out of order, the hydraulic clutch cannot be disengaged, which is very dangerous.

[0005]

[Means for Solving the Problems]

 The present invention has the following structure in order to solve the above problems. That is, in a control hydraulic circuit of a hydraulic clutch type transmission that performs forward / backward movement or speed switching of a traveling vehicle, an emergency switching valve is provided in an oil passage from a hydraulic pump to the hydraulic clutch controlling hydraulic circuit, When the pump is out of order, the emergency switching valve is switched to feed oil from another hydraulic pump to the hydraulic circuit for controlling the hydraulic clutch.

Further, in the control hydraulic circuit of the hydraulic clutch type transmission in which the solenoid valve that opens in the energized state and supplies pressure oil to the hydraulic clutch is interposed, the hydraulic pressure that is input when the pressure oil supply is stopped A safety stop solenoid valve is provided in the oil path between the clutch and the hydraulic clutch switching solenoid valve, and the safety stop solenoid valve switches during a power failure to supply pressure oil to the hydraulic clutch. However, the clutch is disengaged.

[0007]

[Action]

 In the event of a hydraulic pump failure, switching of the emergency switching valve causes pressure oil to be supplied from the other hydraulic pumps to the hydraulic clutch control hydraulic circuit, and normal traveling drive is maintained.

Further, when the solenoid valve is closed due to a failure of the power supply device, switching of the safety stop solenoid valve causes pressure oil to be supplied to the hydraulic clutch that is turned on by stopping the hydraulic pressure supply, and the hydraulic clutch is disengaged. , The traveling vehicle surely stops traveling.

[0009]

【Example】

 The problems and configurations to be solved by the present invention are as described above. Next, the embodiments of the present invention shown in the accompanying drawings will be described. FIG. 1 is a diagram of a hydraulic circuit for controlling a hydraulic clutch that employs the hydraulic emergency circuit of the present invention in a normal state, FIG. 2 is a diagram of a hydraulic pump failure, FIG. 3 is a diagram of a power supply failure, and FIG. Similarly, it is a diagram when the hydraulic pump and the power supply device simultaneously fail. The thick line portion indicates the oil passage to which the pressure oil is supplied.

The hydraulic circuit of the hydraulic clutch of the auxiliary transmission will be described with reference to FIG. Note that FIG. 1 discloses a state in which each of the hydraulic clutches described later is disengaged to drive the input shaft 6 of the transmission case at a high speed forward drive. The auxiliary transmission is arranged between the output shaft 1 of the engine E and the mission case input shaft 3 with a built-in transmission, and switches the transmission case input shaft between low speed forward drive, high speed forward drive and reverse drive. , Composed of hydraulic clutch.

The output shaft of the engine E has a double shaft structure and forms a traveling drive shaft 1 and a PTO shaft 2. The traveling drive shaft 1 is located outside the output shaft, and the high speed forward clutch FH is mounted on the traveling drive shaft 1. The high-speed forward clutch FH is disengaged during the pressure oil supply, and when the pressure oil supply is stopped, the clutch is turned on by the restoring force of the spring to follow the rotational drive of the traveling drive shaft 1 and 'Is driven and is taken over by the transmission in the mission case.

When the high speed forward clutch FH is disengaged, either of the low speed forward clutch FL and the reverse clutch R, which are annularly mounted on the input shaft 3, is engaged, whereby the traveling drive shaft 1 The input shaft 3 drives the traveling shaft 1 ′ via 5 and 4 by following either of the clutch gears 6 and 7 meshing with the gears annularly mounted on the input shaft 3. Further, a whirling prevention clutch C is mounted on the input shaft 3. This is because when gear shifting is performed in the transmission in the transmission case, smooth gear engagement is not possible when the input shaft 3 is rotating, so the low speed forward clutch FL, the high speed forward clutch FH, and the reverse clutch. Even when all the R clutches are disengaged, the input shaft 3 is forcibly braked by inertial force so as not to rotate, so that a reliable gear shift operation can be performed.

The hydraulic oil for controlling the hydraulic clutch of the auxiliary transmission configured as described above is sent by the hydraulic pump P1. An emergency switching valve V1 is disposed between the oil passages 8 and 9 from the hydraulic pump P1. During normal times, the emergency switching valve V1 is moved to the left side by the pilot pressure and the oil passage 8 The passage 9 is open. The oil passage 9 is branched and is a solenoid valve for switching each hydraulic clutch, and is connected to a high speed forward clutch valve S1, a whirling prevention clutch valve S2, a low speed forward clutch valve S3, and a reverse clutch valve S4 which are opened when energized. The oil passages are connected, and further the oil passages are connected from the clutch valves to the hydraulic clutches FH, C, FL and R, respectively.

The operation of each clutch valve is based on a shift operation by an operator. First, when low speed forward drive or reverse drive is selected, the low speed forward clutch valve S3 or the reverse clutch valve S4 is opened, pressure oil is sent to the low speed forward clutch FL or the reverse clutch R, and either clutch is engaged. However, on the other hand, the high speed forward clutch valve S1 is also opened, pressure oil is sent to the high speed forward clutch FH, and as described above, the high speed forward clutch FH is disengaged. In the case of selecting high speed forward, the low speed forward clutch valve S3 and the reverse clutch valve S4 are closed, the reverse low speed clutch FL and the reverse clutch R are disengaged, and the high speed forward clutch S1 is also closed. The pressure oil is not sent to the high speed forward clutch FH, and as described above, the high speed forward clutch FH is turned on by the biasing force of the spring. Further, when the gear shift operation in the transmission case is performed, each hydraulic clutch is disengaged, the drive of the input shaft 3 is disengaged, and the anti-sway clutch valve S2 is operated so as to brake the input shaft 3. Is opened and the anti-sway clutch C is engaged.

A safety stop solenoid valve V2 is provided in the oil path between the high speed forward clutch valve S1 and the high speed forward clutch FH. When the power supply to the clutch valves S1 to S4 is stopped due to a failure or the like, the safety stop solenoid valve V2 is closed by the high speed forward clutch valve S1 so that the high speed forward clutch FH is turned on. Is likely to run out of control, so in the event of a power failure the spring bias moves to the right to open the oil passage from the oil passage 9 to the high speed forward clutch FH, and apply pressure oil to the high speed forward clutch FH. It is for sending to disengage the clutch to stop traveling. In normal times, the clutch valves S1 to S4, which are solenoid valves, are opened / closed by a power supply device (not shown), and the safety stop solenoid valve V2 is normally energized and is set to the left side. The oil passage 10 from the forward clutch valve S1 and the oil passage 11 to the high speed forward clutch FH are opened, and when the high speed forward clutch FH is disengaged, the high speed forward clutch valve S1 is opened. The pressure oil is configured to flow from the oil passage 10 to the oil passage 11.

Further, P2 in the drawing is a hydraulic pump for power steering, and an oil passage is extended from the hydraulic pump P2 for power steering, and an oil passage 12 connected to the emergency switching valve V1 and a relief valve 14 are provided. It is interposed and branched to an oil passage 13 that supplies a lubricating passage to the engine output shaft having the traveling drive shaft 1. In normal times, the emergency switching valve V1 is set to the left side as described above. In addition, the oil passage 9 from the oil passage 12 to the clutch valves is closed.

Next, the hydraulic circuit for controlling the hydraulic clutch when the hydraulic pump fails will be described with reference to FIG. Note that FIG. 2 shows the high-speed forward drive state when the hydraulic pump fails. In normal times, as described above, the pressure oil circuit of the auxiliary transmission is fed by the hydraulic pump P1, but if the hydraulic pump P1 fails, each hydraulic clutch will be opened regardless of whether the clutch valve is opened or closed. Pressure oil is not sent to the clutches, making it impossible to control each clutch. Then, due to the decrease in oil pressure, the low speed forward clutch FL, the reverse clutch R, and the anti-sway clutch C are disengaged, but the high speed forward clutch FH is turned on, which may lead to vehicle runaway or damage to the clutch or shaft due to overload. Therefore, it is desirable that the hydraulic pump P1 should be ready for oil supply from other places to each clutch valve and each hydraulic clutch when the hydraulic pump P1 fails. In the present invention, the emergency switching valve V1 moves to the right side by the restoring force of the vane when the hydraulic pump P1 fails and the hydraulic pressure drops, so that the hydraulic switching pump V1 moves from the oil passage 8 to the oil passage 9 Is closed, and the oil passage 9 is opened from the oil passage 12 from the power steering hydraulic pump P2. That is, oil is fed from the power steering hydraulic pump P2 to the oil passage 9, and oil feeding to each clutch valve and hydraulic clutch is maintained.

Further, when the emergency switching valve V1 is switched due to the failure of the hydraulic pump P1, the operator is alerted by an alarm lamp or a buzzer by the switching of the valve. As a result, the operator can detect the failure of the hydraulic pump P1, and the sudden failure of the hydraulic pump P1 will not cause a situation such as a vehicle runaway. Oil is sent to the hydraulic clutch of the transmission, and normal drive is maintained, so that the operator can deal with the alarm without rushing.

Next, referring to FIG. 3, a hydraulic emergency circuit for emergency traveling stop when the solenoid valve is in a power failure state due to a failure of the power supply device or the like will be described. When the power supply device fails, all clutch valves S1 to S4 are shut off due to a power failure, and the pressure oil supply from each clutch valve to each hydraulic clutch is stopped. At this time, the hydraulic clutches FL, R, C are disengaged, but the high-speed forward clutch FH is energized by the urging force of the spring and drives the traveling shaft 1'to rotate at high speed, which is extremely dangerous because the machine runs out of control. However, when a power failure occurs, the safety stop solenoid valve V1 is set on the right side by the restoring force of the spring, and the direct connection oil passage from the oil passage 9 to the high speed forward clutch valve S1 is opened. Then, the pressure oil is fed from the oil passage 9 to which the pressure oil is constantly supplied to the oil passage 11, the pressure oil is supplied to the high speed forward clutch FH, and the clutch is disengaged. As a result, the traveling shaft 1'stops driving, and the traveling of the airframe stops. Even when the power supply unit fails, the worker is alerted to the abnormality. Even if an alarm is issued in this way, the vehicle can be stopped without fail, allowing workers to calm down safely and deal with abnormalities.

Next, a case where the hydraulic pump and the power supply device simultaneously fail will be described with reference to FIG. When the tractor is heavily impacted, it is possible that both will fail at the same time. The solenoid valve goes into a power failure state due to a failure of the power supply device, so that the safety stop solenoid valve V2 is switched to prevent the high-speed forward clutch valve from entering into a runaway state, and the oil passage Although the oil is forcibly fed to the high speed forward clutch FH from No. 9, when the hydraulic pump P1 is out of order, the oil pressure in the oil passage 9 is a negative pressure and the oil is forced to be fed. Not done. However, in the present invention, when the hydraulic pump fails, the emergency switching valve V1 is switched and oil is sent to the oil passage 9 from the power steering hydraulic pump P2, so that the high speed forward clutch FH is reliably supplied with pressure oil. It can be sent to disengage the clutch and stop running. In this way, by disposing both the emergency switching valve V1 and the safety stop solenoid valve V2, the vehicle can be reliably stopped when both the hydraulic pump and the power supply device fail. .

[0021]

[Effect of device]

 The present invention has the following effects by being configured as described above. That is, as in claim 1, an emergency switching valve is provided in the oil passage from the hydraulic pump to the hydraulic clutch controlling hydraulic circuit, and when the hydraulic pump for supplying oil to the hydraulic circuit fails, the valve switches to another valve. Since the hydraulic oil is supplied from the hydraulic pump, the hydraulic clutch can be controlled normally even if the hydraulic pump fails, and the on / off of the hydraulic clutch cannot be controlled by stopping the hydraulic oil supply. As a result, it is possible to prevent the vehicle from running out of control and damaging the members of the traveling system such as the clutch and shaft, and the operator can calm down safely and deal with the failure of the hydraulic pump. .

According to a second aspect of the present invention, in the control hydraulic circuit of the hydraulic clutch type transmission, the solenoid valve is opened in the energized state to supply pressure oil to the hydraulic clutch, and the hydraulic clutch is disengaged. Since a safety stop solenoid valve is provided in the oil passage between the hydraulic clutch that enters when the power is stopped and the solenoid valve for switching the hydraulic clutch, the safety stop solenoid valve can be used in the event of a power failure such as a power failure. A hydraulic emergency circuit has been provided to supply hydraulic oil to the hydraulic clutch that is turned on when the valve is switched and hydraulic oil is not supplied, so that the hydraulic clutch does not run out of control in the event of a power outage. In addition, it is possible to reliably stop the traveling of the aircraft, which contributes to the safety of workers and the maintenance of the aircraft.

[Brief description of drawings]

FIG. 1 is a normal view of a hydraulic circuit for controlling a hydraulic clutch adopting the hydraulic emergency circuit of the present invention.

FIG. 2 is likewise a diagram when the hydraulic pump fails.

FIG. 3 is a diagram of the same when a power supply device fails.

FIG. 4 is a diagram of the same when a hydraulic pump and a power supply device simultaneously fail.

[Explanation of symbols]

 V1 Emergency switching valve V2 Safety stop solenoid valve S1 High-speed forward clutch valve S2 Anti-rotation clutch valve S3 Low-speed forward clutch valve S4 Reverse clutch valve FH High-speed forward clutch FL Low-speed forward clutch R Reverse clutch C Anti-rotation clutch 1 Travel drive axis

Claims (2)

[Scope of utility model registration request] 1. In a control hydraulic circuit of a hydraulic clutch type transmission for performing forward / backward movement or speed switching of a traveling vehicle, an emergency switching valve is provided in an oil passage from a hydraulic pump to the hydraulic clutch controlling hydraulic circuit. A hydraulic emergency circuit of a hydraulic clutch type transmission, characterized in that, when the hydraulic pump is out of order, the emergency switching valve is switched to feed oil from another hydraulic pump to the hydraulic clutch control hydraulic circuit. . 2. A hydraulic circuit that is opened when pressure oil supply is stopped in a control hydraulic circuit of a hydraulic clutch type transmission that opens a solenoid valve in an energized state to supply pressure oil to a hydraulic clutch and disconnect the hydraulic clutch. A safety stop solenoid valve is provided in an oil passage between the clutch and the hydraulic clutch switching solenoid valve, and the safety stop solenoid valve is switched at the time of a power failure, and the safety clutch is switched from another path to the hydraulic clutch. A hydraulic emergency circuit for a hydraulic clutch type transmission characterized in that pressure oil is supplied and the clutch is disengaged.