JPH02253043A - Control device for vehicular hydraulic actuated transmission gear - Google Patents

Abstract

PURPOSE:To relieve the established shock of a backward power transmission system by starting the boost-buffer action at lower pressure by an accumulator for a shared-forward-backward clutch at the established time of the backward power transmission system compared to the speed change time to the specific power transmission system. CONSTITUTION:At the time of speed change in the forward range of a manual valve 9 to a specific power transmission system, oil flows only into the first accumulator chamber 20 of an accumulator A4 for a shared-forward-backward hydraulic clutch, and when its pressing force exceeds the energizing force of an elastic member 16, a piston 15 starts its receding motion and the buffer action is started. At the time of changing over to the backward range, however, oil flows not only into the first accumulator 20 but also into the second accumulator 21, the piston 15 recedes against the energizing force of the elastic member 16 during the time of relatively low pressure, and the buffer action is started. At this time, the volume of the accumulator is enlarged according to the sum of the pressure receiving areas S1, S2 of both chambers 20, 21. The established shock of the backward power transmission system can be thus relieved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention provides a plurality of forward transmission systems established by separate hydraulic clutches, and a predetermined transmission system of these forward transmission systems and a hydraulic clutch. The present invention relates to a control device for a hydraulically operated transmission for a vehicle, which is equipped with a reverse transmission system that shares the same functions as the reverse transmission system.

(Prior Art) Conventionally, Japanese Patent Application Laid-Open No. 61-233248 discloses a transmission system for forward speeds of 1st to 4th speeds established by hydraulic clutches of 1st to 4th speeds, a 4th speed transmission system, and a 4th speed transmission system. In a hydraulically operated transmission for a vehicle that is equipped with a reverse transmission system that shares a hydraulic clutch, a manual valve is provided in the hydraulic circuit that controls oil supply and discharge to these hydraulic clutches, and when the manual valve is switched to the forward range, the shift occurs. Selectively lubricating the hydraulic clutches of 1st to 4th speeds via a valve to shift gears from 1st to 4th speeds;
When the manual valve is switched to the reverse range, the 4-speed pressure clutch is supplied with oil via the servo valve that operates the selector gear that selectively establishes the 4-speed transmission system as the reverse transmission system, and the selector gear is moved to the reverse side. A reverse transmission system is established by the switching operation of the 1st to 4th gear hydraulic clutches and the engagement of the 4th gear hydraulic clutches, and each clutch oil passage connected to each of the 1st to 4th gear hydraulic clutches is connected to a sudden increase in the oil pressure supplied to each hydraulic clutch. It is known that an accumulator is connected to buffer the sudden rise in speed to reduce shift shock.

(Problems to be Solved by the Invention) The accumulator is configured to receive oil into an accumulator chamber on the front side of the accumulator piston while moving the accumulator piston housed in the accumulator against an elastic member on the back side of the accumulator. , the oil pressure rises until the oil pressure supplied to the clutch rises from the lower limit pressure corresponding to the initial elastic force of the elastic member to the upper limit pressure corresponding to the elastic force when the accumulator piston reaches the stroke end. buffered,
This buffer time becomes longer as the stroke volume of the accumulator piston, that is, the accumulator capacity increases.

By the way, the accumulator for the 4-speed hydraulic clutch has elasticity that matches the buffering characteristics required for the shift to 4th gear U and ν, in order to reduce the shift shock that occurs when shifting to 4th gear in the forward range of the manual valve. Generally, the spring rate of the member and the accumulator chamber are set, and as a result, it may not be possible to satisfactorily absorb the shock that occurs when the reverse transmission system is established by switching the manual valve to the reverse range.

That is, since switching to the reverse range is generally performed with the engine in an idling state, the 4th gear hydraulic clutch begins to engage at a lower hydraulic pressure than when shifting to 4th gear. If the lower limit pressure at which the accumulator piston begins to withdraw becomes too high, the 4-speed hydraulic clutch may engage before the accumulator can provide a pressure increase buffering effect, and the shock may not be absorbed.

In this case, it is conceivable to add an accumulator dedicated to the reverse range as an accumulator for the 4-speed hydraulic clutch, that is, a hydraulic clutch shared by the reverse transmission system and a predetermined forward transmission system, but such a configuration is difficult due to space, weight, etc. This has problems and is not practical.

In view of the above points, the present invention uses a single accumulator to satisfactorily absorb shock not only when shifting to the predetermined transmission system in the forward range but also when establishing the reverse transmission system. Its purpose is to provide equipment.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a plurality of forward transmission systems established by separate hydraulic clutches, and a predetermined transmission system among these forward transmission systems. and a reverse f-drive system that shares a hydraulic clutch, and by switching to the forward range of a manual valve provided in the hydraulic circuit that controls oil supply and discharge to these hydraulic clutches, the predetermined transmission system and the reverse transmission system are connected. The predetermined transmission system is established when the shared hydraulic clutch is refueled, and the reverse transmission system is established when the shared hydraulic clutch is refueled by switching the manual valve to the reverse range; An accumulator is connected to the clutch oil path leading to the shared hydraulic clutch to buffer a sudden rise or fall in the oil pressure supplied to the shared hydraulic clutch, and the accumulator has a stepped shape having a large diameter piston portion and a small diameter piston portion. an accumulator piston is inserted into the accumulator to define at least two accumulator chambers facing each piston portion of the accumulator piston, one first accumulator chamber being in constant communication with the clutch oil passage, and the other accumulator chamber being in constant communication with the clutch oil passage. The second accumulator chamber of the manual valve is switched to the reverse range and communicated with the clutch oil passage.

(Function) The pressure receiving area of the piston part facing the first accumulator chamber of the accumulator piston is 31, the pressure receiving area of the piston part facing the second accumulator chamber is 82, and the leaving stroke of the accumulator piston is 11. Assuming that the hydraulic pressure is P, when shifting to a predetermined transmission system in the forward range of the manual valve, the flow only flows into the first accumulator chamber, and the accumulator piston receives pxs, pxs,
When this pressing force exceeds the biasing force of the elastic member of the piston, the piston begins to retract, and then, when the piston retracts by L and reaches the stroke end, the buffering action ends. , the accumulator capacity at this time is S+Xfl.

On the other hand, when switching the manual valve to reverse range,
Ura flows not only into the accumulator chamber but also into the second accumulator chamber, and the accumulator piston is filled with PX (SI
A pressing force of +32) is applied, and thus the accumulator piston begins to retire while P is at a relatively low pressure! A buffering effect is performed until the employee leaves work, and the accumulator capacity becomes (S++32)X,Q.

Therefore, when the reverse transmission system is established, the buffering action starts at a relatively low pressure, the accumulator capacity increases and the buffering time becomes longer, and the shared hydraulic clutch engages with the suspension under this damping action. The shock of establishing the reverse transmission system is alleviated.

(Example) Referring to FIG. 1, (1) shows a transmission that performs four forward speeds and one reverse speed.
A forward drive shaft is connected between an input shaft (1a) connected to the vehicle through a fluid torque converter (3) and an output shaft (1b) connected to the drive wheels (4) of the vehicle through a differential gear (5). 1st to 4th speed transmission system (Gl) (G2) (03) (G4
) and a reverse transmission system (GR), and each forward transmission system (
OL) (G2) (G3) (G4) each hydraulic clutch (C1) (C2) (C3) (C
4), and each hydraulic latch (CI) (C2)
(C3) By the engagement of (C4), each transmission system (Gl
) (G2) (G3) (G4) are selectively established, and the reverse transmission system (CI?) is set to the 4-speed transmission system (
G4) and a 4-speed hydraulic clutch (C4) are shared, and both transmission systems (G4) (GR) are connected to the left forward side and the right side in the drawing of the selector gear (6) on the output shaft (1b). It is now established selectively by switching to the reverse side.

In the figure, (7) is a one-way clutch that intervenes in the 1st-speed transmission system (G1), which operates to allow over-rotation of the output shaft (1b) side, and by supplying oil to the 2nd-speed hydraulic clutch (C2), the 2nd-speed transmission is transmitted. When the system (G2) is established, the first speed transmission system (G
The power transmission via l) is automatically stopped.

Each of the hydraulic clutches (C1,) (C2) (C3)
(C4) is supplied and discharged from the hydraulic source (8) as shown in Figure 2.
), a manual valve (9), and a shift valve unit consisting of a plurality of shift valves (IG, and a servo valve l' for forward/reverse switching that connects a shift fork (6a) that engages with the selector gear (6)). 11), and the manual valve (9) is controlled by a shift lever inside the passenger compartment to select "P" for parking, rRJ for reverse, "N" for neutral, and rDJ for automatic gear shifting. It can be freely switched between 6 ranges: "S" and "2" for holding 2nd speed.
The first oil passage (Ll) leading to shift valve unit q■ is connected to via the manual valve (9), and the second oil passage (1, 2) branched from the first oil passage (old) is connected to 1-speed hydraulic clutch (
C1) is constantly supplied with oil at line pressure, and each shift valve of the shift valve unit (IO) is switched and controlled by a signal from an electronic control circuit aD as described later.
2-speed hydraulic clutch (C) via the third oil passage (L3).
2) and the 3rd speed hydraulic clutch (C) via the fourth oil passage (L4).
3) and further selectively supplying oil from the unit (IG to the 4th speed hydraulic clutch (C4) via the fifth oil passage (L5), the manual valve (9), and the sixth oil passage (L6). by 1
It performs automatic gear shifting from 1st to 4th speeds, and in the "2" range, the shift valve unit (1 (11) is connected to the 2nd speed hydraulic clutch (C2).
In the rRJ range, the servo valve (11) is supplied from the manual valve (9) through the seventh oil passage (L7). Supply oil and shift fork (6a) via the servo valve (11).
to the right as shown by the imaginary line to switch the selector gear (6) to the reverse side, and also move the servo valve (from Iv to the 8th oil passage (Lli), the manual valve (9), and the 6th oil passage (L6) A 4-speed hydraulic clutch (C4) is supplied with oil via the 4-speed hydraulic clutch (C4) to establish a reverse transmission system (GI?).

Note that the sixth oil passage (L G ) is selectively connected to the fifth oil passage (L5) in the rDJ and rSJ ranges and to the eighth oil passage (L8) in the rRJ range.

The electronic control circuit (2) is composed of a microcomputer, and is equipped with a position sensor (1) for the manual valve (9).
31), the signal from the engine throttle opening sensor (132), and the signal from the vehicle speed sensor (13a), and input the signal from the manual valve (9) rDJ rsJ.
In range, according to predetermined shift characteristics defined using throttle opening and vehicle speed as parameters, which hydraulic clutch (C2) (C3) (0
4) also outputs a 1st speed signal that does not lubricate the 1st speed transmission system (G
1), outputs a 2nd speed signal to lubricate the 2nd speed hydraulic clutch (C2) in the 2nd speed region and lubricates the 2nd speed transmission system (G2), and 3 to lubricate the 3rd speed hydraulic clutch (C3) in the 3rd speed region. A speed signal is outputted to supply oil to the 3rd speed transmission system (G3), and a 4th speed signal is outputted to supply oil to the 4th speed hydraulic clutch (C4) in the 4th speed region.
G4).

In the figure, (AI), (A2), (83), and (A4) indicate the accumulators installed to buffer sudden pressure changes when oil is supplied and discharged from each hydraulic clutch (CI), (C2, C3, and C4). These accumulators are designed to reduce shift shock.

By the way, the accumulator (A4) for the 4-speed hydraulic clutch (C4), which is a shared hydraulic clutch for the 4-speed transmission system (G4) and the reverse transmission system (GR), is connected to the rDJ of the manual valve (9).
When shifting to 4th speed in rsJ range and switching to rRJ range of manual valve (9), reverse transmission system
The system is configured as follows so as to be able to cope with both the establishment of GR).

That is, the accumulator (A4) is an accumulator that is integrated into the valve block in the mission case.] 1 ] 2 A stepped hole (14a) formed in the rotor body a @ extends to the large diameter piston part (15a) and beyond it. A stepped-shaped accumulator piston (15) having a small diameter piston portion (151) is fitted between the piston (+51) and an end cap (14b) fitted to the open end of the accumulator body (I4). A coil spring (IO) is interposed between the first accumulator chamber (I71) and the small diameter piston between the large diameter piston part (15a) and the intermediate step surface of the stepped hole (14a) facing the large diameter piston part (15a). Section (15b)
A second accumulator chamber (18) is defined between the top surface of the stepped hole (14a) and the bottom surface of the stepped hole (14a), and the first accumulator chamber (17) is connected to the sixth oil passage (L8) and the second accumulator chamber (18). The second accumulator chamber (18) was communicated with the eighth oil passage (L8).

In addition, in this embodiment, a guide sleeve (15) is provided at the tail end of the accumulator piston (ISl) and has a smaller diameter than the large diameter piston part (15a) and fits inside the end cap (14b).
c), a back pressure chamber (19) is defined on the outer periphery of the guide sleeve (15c), and a throttle pressure Pθ corresponding to the throttle opening of the engine is input into the back pressure chamber l″19. I did it like that.

The accumulator piston a9 has a large diameter piston portion (
15a) can be withdrawn to the position where it abuts the stopper ■ constituted by the tip of the end cap (141+), and the withdrawal stroke is controlled by the pressure-receiving area facing the first accumulator chamber (+71) of the large-diameter piston portion (15a). 31,
Second accumulator chamber q of small diameter piston part (151))
The operation of this embodiment will be explained assuming that the pressure receiving area facing ε is 82 and the initial spring force of the coil spring GO is F.

4 in rDJ rsJ range of manual valve (9)
When shifting to a higher speed, oil is not supplied to the 8th oil passage (L8), so oil pressure is supplied to the 4th speed hydraulic clutch (C4) only to the first accumulator chamber (17) that communicates with the 6th oil passage (L6). P
acts, and a predetermined lower limit pressure P+ (=
When the accumulator piston q9 rises to F+/S+), the accumulator piston q9 begins to withdraw, and this withdrawal buffers the increase in the supply hydraulic pressure P, and when the piston (15) comes into contact with the stopper ■, the supply hydraulic pressure P returns to the hydraulic pressure source (8). The line pressure is increased to the line pressure P+ supplied from the

Thus, the pressure increase buffering characteristic when shifting to 4th gear is as shown by line a in Figure 3, and the 4th gear hydraulic clutch (C4) is smooth in the buffer region during which the accumulator piston 05) is retracted by a stroke of 1. engage with. By the way, the oil pressure that causes the engagement of the clutch changes depending on the engine load, that is, the throttle opening, or it changes depending on the back pressure chamber (I9) as described above.
When the throttle pressure Pθ is input to the engine, the range of oil pressure that buffers the pressure increase changes according to the throttle pressure Pθ, and the 4th speed hydraulic clutch (C4) engages in the buffer range regardless of the change in the throttle opening. Shift shock is alleviated.

When switching the manual valve (9) to the rRJ range to establish the reverse transmission system (GR), connect the 8th oil passage (1, 8) and the 6th oil passage (L 6 ) from the servo valve ('11). through 4
The Hayaura pressure clutch is supplied with oil, and the second accumulator chamber (+
The supply oil pressure P to the 4th speed hydraulic clutch (C4) also acts on 81, and P is a predetermined pressure P lower than the lower limit pressure P1.
2 (=FI/(SI+32)), the accumulator piston q! The increase in the inter-supply oil pressure P, which occurs by the stroke I when the stroke i) starts to leave, is buffered, and thus the pressure increase buffering characteristic becomes as shown by the line b in FIG. 3. In this case, even if the stroke of the accumulator piston (Is) is the same, the first and second accumulator chambers 117)
(Since oil flows into 1&, the capacity becomes larger than when shifting to 4th gear, where oil flows only into the 1st accumulator chamber (17). When the reverse transmission system (GR) is established, the line a in Figure 4 is shown, and the line b in the same figure is shown when the reverse transmission system (GR) is established.In this way, when the reverse transmission system (GR) is established, the lower limit pressure P2 that produces a buffering effect is 4-speed hydraulic clutch (
C4) is gradually engaged in the buffer region, and the establishment shock of the reverse transmission system (GR) is alleviated.

Furthermore, if the accelerator pedal is depressed at the same time as switching to the reverse range, the throttle pressure Pθ will rise to the hydraulic pressure range that produces a buffering effect, and the 4th speed hydraulic clutch (C4) will smoothly operate in the buffering range in this case as well. engage.

By the way, the applicant of this application previously filed the patent application Sho Gl-230999.
Select the servo valve (11) as shown in the second figure]
5 Locking means (11
a) so that it can be locked, and the manual valve (9) is set to rRJ.
When switching from range to rNJ rPJ range, hold the servo valve (11) in the reverse position and turn the manual valve (
9) to the forward range of rDJ rSJ r2J, the manual valve (9) to the 9th oil passage (1, 9
) has been proposed in which the servo valve (11) is switched to the forward position by hydraulic pressure input through the valve. Furthermore, in this model, in the rPJ range of the manual valve (9), hydraulic pressure is input to the servo valve ('IT) via the seventh oil path (L7) to switch and hold the servo valve (11) in the reverse position. I have to. In addition, in the rPJ range, the 6th Uraji (L6)
Since the connection between the engine and the eighth oil passage (L8) is cut off, the fourth-speed hydraulic clutch (C4) is not supplied with oil.

When such a configuration is adopted, in the "P" range, the seventh oil passage (1, 7) is connected to the eighth oil passage (L8) via the servo valve a1).
) is supplied with oil to the second accumulator chamber ('lε
This causes the accumulator piston (I5) to retire at the end of its stroke. Therefore, the manual valve (9
) is switched from the "P" range to the rRJ range,
The buffering effect of the accumulator piston (+51) cannot be obtained.

In order to eliminate this problem, the second accumulator chamber (
'181 without directly connecting it to the eighth oil passage (L8).
Add a port connected to I& to the manual valve (9),
Connect the second accumulator chamber (181) to the eighth oil passage (L8) or the sixth oil passage (LG) in the rRJ range,
In other ranges, the oil passage may be configured to be open to the atmosphere.

Further, which shift valve provided in the shift valve unit is controlled to be switched to different shift positions for the rRJ range and the rPJ range by the electronic control circuit ab, and the shift valve is connected to the second accumulator chamber (port connected to 181 and the eighth oil Road (L
8), connect the second accumulator chamber (+81) to the eighth oil passage (L 8 ) via the shift valve at the shift position of the rRJ range, and
The shift position of the range may be opened to the atmosphere.

(Effects of the Invention) As described above, according to the present invention, by using a single accumulator for a common hydraulic clutch for a predetermined forward transmission system and a reverse transmission system, when the reverse transmission system is established, the transmission system is transferred to the predetermined transmission system. It is possible to start the pressure increase buffering effect at a lower pressure and to continue the buffering effect for a longer time than when changing gears, which has the effect of alleviating the establishment shock of the reverse transmission system.

[Brief explanation of drawings]

Fig. 1 is a line diagram of an example of a transmission to which the present invention is applied, Fig. 2 is a block diagram of a transmission hydraulic circuit including a sectional view of an accumulator for a shared hydraulic clutch, and Fig. 3 shows an accumulator on the horizontal axis. FIG. 4 is a diagram showing the pressure increase buffering characteristic of the accumulator with respect to the stroke of the piston, and FIG. 4 is a diagram showing the pressure increase buffer characteristic with the capacity of the accumulator taken on the horizontal axis. (1)...Transmission machine (G4)...4-speed transmission system (specified transmission system) (GR)
...1 reverse transmission system (C4)...4-speed hydraulic clutch (common hydraulic clutch) (
9)...Manual valve (LB)/6th channel (clutch oil channel) (A4)...Accumulator sowing for common hydraulic clutch...Accumulator piston (15a)...Large diameter piston part (15b) ...Small diameter piston part■...First accumulator chamber 12'I)...Second accumulator chamber

Claims (1)

[Claims] It is equipped with a plurality of forward transmission systems established by separate hydraulic clutches, and a reverse transmission system that shares a hydraulic clutch with a predetermined transmission system among these forward transmission systems, and provides supply and discharge to and from these hydraulic clutches. When the manual valve provided in the hydraulic circuit for controlling oil is switched to the forward range and the shared hydraulic clutch of the predetermined transmission system and the reverse transmission system is supplied with oil, the predetermined transmission system is established, and the manual valve is switched to the forward range. The reverse transmission system is established when the shared hydraulic clutch is refueled when switching to the reverse range, and the oil pressure supplied to the shared hydraulic clutch is caused to suddenly rise in the clutch oil path leading to the shared hydraulic clutch. In this device, a stepped accumulator piston having a large diameter and a small diameter piston portion is inserted into the accumulator, and at least two pistons facing each piston portion of the accumulator piston are inserted into the accumulator. an accumulator chamber is defined, one first accumulator chamber is always communicated with the clutch oil passage, and the other second accumulator chamber is communicated with the clutch oil passage when the manual valve is switched to the reverse range. A control device for a hydraulically operated transmission for a vehicle, which is characterized by: