JPH0379861A - Gear shift cylinder drive unit for transmission - Google Patents

Abstract

PURPOSE:To promote the efficiency of oil pressure and the decrease of surge pressure at the time of gear shift by outputting a valve closing signal to a main solenoid valve first at the time of terminating gear shift, and after the lapse of the specified time, outputting a valve opening signal to auxiliary solenoid valves. CONSTITUTION:A controller 17 opens a main solenoid valve VM in the case of performing gear shift from backward to forward, and in the valve closed state of an auxiliary solenoid valve VF on and the valve opened state of an auxiliary solenoid valve VR off, supplies operating oil from an accumulator 15 into the rod chamber R1 of a gear shift cylinder 8 and discharges operating oil in a bottom chamber R2 into a tank 12. At the time of terminating gear shift, the auxiliary solenoid valve VR is switched on to be closed, then the main solenoid valve VM is switched on to be closed, and after the lapse of the spacified time, the auxiliary solenoid valves VF, VR are switched off to be opened, thus promoting the efficiency of oil pressure and the decrease of surge pressure at the time of gear shift due to dispersion in the responsiveness of each solenoid valve.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a drive device for a gear shift cylinder of a transmission.

[Prior Art] Figure 2 shows the drive system mechanism of a forklift truck equipped with an automatic transmission.
The transmission is transmitted to the automatic transmission 3 via the automatic transmission 3, and automatic gear shifting! f13 is configured to move the running drive wheels 5 forward and backward at a predetermined gear ratio via a differential gear Bi@4. A dry single-plate clutch 2 that turns on and off the output of the engine 1 is connected to a stroke star of a rod 6a that extends based on the drive of a clutch control actuator 6.
connection status is adjusted. The automatic transmission 3 changes speed by being switched between 1st speed (low speed) and 2nd speed (high speed) by driving the gear shift cylinder 7.
The gear position of automatic transmission 3 is advanced by driving, and the gear position of automatic transmission 3 is advanced from
It is designed to switch between three positions: normal and reverse.

FIG. 3 shows an example of an automatic transmission equipped with a power unit 9. In the power unit 9, an oil pump 11 driven by a motor 10 supplies hydraulic oil from an oil tank 12 to an accumulator 15 via a relief valve 13 and a check valve 14. Further, the pressure switch 16 is turned on when the hydraulic oil pressure in the accumulator 15 is below a first set value, and is turned off when the second set value is greater than the first set value to turn the motor 10 on and off. The oil pressure is kept within a certain range. A main solenoid valve VM is provided in the middle of the piping between the gear shift cylinder 7.8 and the accumulator 15, and sub solenoid valves VR, VF, Vl,
By opening and closing Vl, the hydraulic oil of the seventh accumulator 15 is supplied to or discharged from the bottom chamber or rod chamber of the gear shift cylinders 7 and 8, and gear switching is performed by the telescoping operation of the gear shift cylinders 7 and 8. That is, solenoid valves VH, VR, \J
F.

A signal from the controller 17 that controls Vl and Vl is
For example, when moving the forward and reverse gears in the forward direction,
As shown in FIG. 4, at time T1, the solenoid valves VH, VF, Vl
, Vl start driving at the same time, the gear starts moving toward the forward gear side. Then, when the gear enters the target position, time T2
After driving the sub solenoid valve VR to stop the gear, at time T
3 turns off all solenoid valves. In addition, the main solenoid valve VH normally closed tie 7, the sub solenoid valve VR, V', Vl
, Vl are each of the normally open type.

[Problem to be solved by the invention] However, when the solenoid valves are simultaneously driven at time T1,
Due to variations in the responsiveness of the N solenoid valves, the sub solenoid valves VF, Vl, and Vl may operate later after the main Nm valve VH opens. In this case, the hydraulic pressure LtV)l −+VF
-+VR, and C, the oil suddenly flows to the oil tank 12 through Vl4 → V2 → Vl, resulting in wasted hydraulic pressure. In addition, when the hydraulic oil is rapidly flowing, the sub solenoid valves Vr and V1゜■2 are closed, which generates a large surge pressure, which causes the pressure switch 16 to malfunction, causing the switch 16 to operate many times and reducing its durability. There was a problem with the decline.

Similarly, when all the solenoid valves are de-energized at the same time at time T3, the main solenoid valve V
The sub-electromagnetic valves VR, VF, Vl, and V2 may open earlier than H closes. In this case, the oil pressure is VH→VF −+VR1 or VH−+V2→v1
The oil suddenly flows through the oil tank 12 and wastes hydraulic pressure. In addition, since the main solenoid valve VH closes when hydraulic oil is rapidly flowing, a large surge pressure is generated, which causes the pressure switch 16 to malfunction, causing the switch 16 to operate many times and reducing durability. Ta.

An object of the present invention is to provide a drive device for a gear shift cylinder of a transmission that can improve the efficiency of hydraulic pressure and reduce surge pressure during gear switching caused by variations in response of each electromagnetic valve.

[Means for Solving the Problems] A first invention includes a gear shift cylinder for performing gear switching, an accumulator that stores hydraulic oil, and a main electromagnetic device provided in the middle of piping between the accumulator and the gear shift cylinder. a sub-electromagnetic valve for supplying or discharging hydraulic oil of the accumulator to a bottom chamber or a rod chamber of the gear shift cylinder to perform gear switching by an expansion and contraction operation of the gear shift cylinder; The gist of the present invention is to provide a drive device for a gear shift cylinder of a transmission, comprising: fi control means for outputting an open ↑ signal to the main solenoid valve after a certain period of time has elapsed after outputting a valve close signal to the auxiliary solenoid valve; do.

A second invention includes a gear shift cylinder for performing gear switching, an accumulator that stores hydraulic oil, a main solenoid valve provided in the middle of piping between the accumulator and the gear shift cylinder, and a bottom chamber of the gear shift cylinder. or a sub solenoid valve for supplying or discharging the hydraulic oil of the accumulator to the rod chamber to switch gears by the telescopic operation of the gear shift cylinder; and a valve closing signal to the main solenoid valve when gear switching is completed. The gist of the present invention is to provide a drive device for a gear shift cylinder of a transmission, comprising a control means for outputting a valve opening signal to the sub-electromagnetic valve after a predetermined period of time has elapsed after the output of the sub-electromagnetic valve.

[Operation] In the first invention, when the control means starts gear switching,
A valve opening signal is output to the main electromagnetic valve after a certain period of time has elapsed after the valve closing signal was output to the sub-electromagnetic valve.

In the second invention, when the control means finishes gear switching,
A valve opening signal is output to the sub-electromagnetic valve after a certain period of time has elapsed after outputting the valve-closing signal to the main electromagnetic valve.

[Example] An example embodying the present invention will be described below with reference to the drawings.

The drive device for the gear shift cylinder of the automatic transmission of this embodiment has the configuration shown in FIGS. 2 and 3, and since each member thereof has already been explained, the explanation thereof will be omitted here.

FIG. 1 shows driving signals (7) from a controller 17 as a control means to each electromagnetic valve V)i, VF, VR, Vl, and Vl. When moving the gear in the forward direction, when the solenoid valves VF, Vl, and Vl are energized simultaneously at time t1, the sub solenoid valves VF, Vl, and Vl close.

Thereafter, at time t2 when a predetermined time Δt1 has elapsed, the main solenoid valve V)l opens. Here, the predetermined time Δt1 is a sufficient period of time necessary for the solenoid valve to respond. At this time, the sub solenoid valve VR remains open. The oil pressure of the accumulator 15 passes through the main solenoid valve VH and enters the rod chamber R1 of the gear shift cylinder 8, which switches gears in the forward and reverse directions of the transmission, pushing the piston in the direction of arrow A in Fig. 3 and moving the gear in the forward direction. drive to switch to.

When the gear enters the target position, first, at time t3, the sub-electromagnetic valve VR is energized to stop the movement of the cylinder 8.

Thereafter, at time t4 when the set time Δt2 has elapsed, the main solenoid valve VH is brought into a de-energized state (closed state). Furthermore, time t5T at which the set time Δt3 has elapsed - sub-electromagnetic valves VF, Vl
? , Vl and Vl are turned off and the valves are opened.

Here, the set time Δt2. and Δt3 is sufficient time required for the solenoid valve to respond.

Similarly, when moving the gear in the reverse direction, the solenoid valve VR,
When Vl and Vl are energized at the same time on the open side t1, the sub solenoid valve V
R, Vl, and Vl are closed, and at time t2 when a predetermined time Δt1 has elapsed, the main solenoid valve VH opens.

At this time, the sub solenoid valve VF remains open. Hydraulic pressure passes through the main solenoid valve VM and enters the rod chamber R of the gear shift cylinder 8.
Since the rod chamber R1 is smaller by the area of the piston, the force pushing the piston is greater in the bottom chamber R2, and the piston is pushed in the direction of the arrow B in Fig. 3. The push gear is driven to switch to the reverse direction.

When the gear enters the target position, the sub-electromagnetic valve VF is energized at time t3 to stop the movement of the gear shift cylinder 8. At time t4 when the set time Δt2 has elapsed, the main solenoid valve VM
Further, the time t5 when the set time Δt3 has elapsed
and sub solenoid valves VF and VR.

Vl　Turn off the power to Vl and open the valve.

In this way, in this embodiment, for example, when starting gear change to the forward side, the main solenoid valve VH is instructed to open after a certain period of time Δt1 has elapsed after the valve closing signal is output to the sub solenoid valves VF, Vl, Vl. Valve signals are now output. the result,
Hydraulic oil does not suddenly flow into the oil tank 12,
There is no needless consumption of oil pressure, and there is no adverse effect on the durability of the motor 10, oil pump 11, etc. Further, since large surge pressure does not occur, the pressure switch 16 can always operate at the set pressure without malfunctioning due to surge pressure, reducing the number of times the pressure switch 16 is operated and improving durability.

Further, after stopping the movement of the gear shift cylinder 8 at time t3, when the solenoid valve is brought into a non-energized state, first,
The main solenoid valve V)l is turned off and the valve is closed, and at time t5 when a certain period of time Δt3 has elapsed, the sub solenoid valves VF, VR, Vl,
A valve opening signal is output to V2 to open the valve. As a result, the hydraulic oil does not suddenly flow into the oil tank 12, and unnecessary oil pressure is not consumed, and the motor 10
, the durability of the oil pump 11 etc. is not adversely affected. Further, since large surge pressure is not generated, the pressure switch 16 can always be operated at the set pressure without malfunctioning due to surge pressure, and the number of operations of the pressure switch 16 is reduced, improving durability.

Note that this invention is not limited to the above embodiments,
For example, in FIG. 1, the time when the solenoid valve VR is turned on may be made to coincide with the time when the main solenoid valve VH is de-energized.

[Effects of the Invention] As detailed above, according to the present invention, it is possible to achieve an excellent effect of increasing the efficiency of hydraulic pressure and reducing surge pressure during gear switching caused by variations in response of each solenoid valve. Demonstrate.

[Brief explanation of drawings]

Figure 1 is a diagram showing the output timing of the drive signal of the solenoid valve in the drive device of the gear shift cylinder of an automatic transmission, Figure 2 is a diagram showing the mechanism of the drive system of a forklift equipped with an automatic transmission, and Figure 3 is FIG. 4 is a block diagram of a drive device for a gear shift cylinder of an automatic transmission, and is a diagram showing the output timing of a drive signal of a solenoid valve to explain the prior art. 8 is a gear shift cylinder, 15 is an accumulator, 17
is the controller as a control means, VH is the main solenoid valve, V
R is the sub solenoid valve, V is the sub solenoid valve.

Claims (1)

[Scope of Claims] 1. A gear shift cylinder for changing gears, an accumulator that stores hydraulic oil, a main solenoid valve provided in the middle of piping between the accumulator and the gear shift cylinder, and a main solenoid valve for the gear shift cylinder. an auxiliary solenoid valve for supplying or discharging the hydraulic oil of the accumulator to a bottom chamber or a rod chamber to perform gear switching by the telescopic operation of the gear shift cylinder; A drive device for a gear shift cylinder of a transmission, comprising: control means for outputting a valve opening signal to the main electromagnetic valve after a predetermined period of time has elapsed after outputting the valve signal. 2. A gear shift cylinder for changing gears, an accumulator that stores hydraulic oil, a main solenoid valve installed in the middle of piping between the accumulator and the gear shift cylinder, and a bottom chamber or rod chamber of the gear shift cylinder. A sub-electromagnetic valve for supplying or discharging the hydraulic oil of the accumulator to perform gear switching by the expansion and contraction operation of the gear shift cylinder; and after outputting a valve closing signal to the main electromagnetic valve when gear switching is completed. and control means for outputting a valve opening signal to the sub-electromagnetic valve after a predetermined period of time has elapsed.