JPS61233248A - Controller of hydraulic type transmission for car - Google Patents

Abstract

PURPOSE:To permit the smooth speed change and prevent the excessive blowing up of an engine by installing shift suppressing apparatuses for cutting off the switching signals of shift valves until the oil pressure of the hydraulic engagement element of a transmission system becomes a prescribed value. CONSTITUTION:When the oil pressure of a second-speed hydraulic clutch C2 is over a prescribed value, the first shift suppressing apparatus 16 is installed so that the governor pressure supplied from a governor valve 12 is not introduced into the third shift valve 103, even if the throttle pressure of the first throttle valve 131 lowers. Further, the second shift suppressing apparatus is installed so that the throttle pressure supplied from the first throttle valve 131 is not introduced into the second shift valve 102 when the oil pressure of the fourth-speed hydraulic clutch C4 is over a prescribed value. Since the shift valves 101, 102, and 103 are not switching-operated until each hydraulic pressure of the hydraulic clutches C1, C2, C3, and C4 becomes each prescribed value, even if the opening degree of the throttle is sharply varied, smooth speed change is permitted, and the excessive blowing up of the engine can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a control device for a hydraulically operated transmission used in an automobile or other vehicle.

(Prior Art) Conventionally, in a control device for a hydraulically actuated transmission that changes gears in four forward speeds, for example, a first shift valve for shifting from 1st to 2nd speed, and a second shift valve for shifting from 2nd to 3rd speed. valve, and a third shift valve for 3rd to 4th speed shifting, and by switching the first shift valve to the upshift side, the 2nd speed hydraulic engagement element is supplied with oil, and the 2nd speed transmission system and the 2nd speed transmission system are refueled. By switching the shift valve to the upshift side, oil is drained from the 2nd speed hydraulic engagement element and oil is supplied to the 3rd speed hydraulic engagement element, and the oil is transferred to the 3rd speed transmission system and the upshift side of the 3rd shift valve. The switching operation drains oil from the 3rd speed hydraulic engagement element and supplies oil to the 4th speed hydraulic engagement element.
A speed transmission system is sequentially and selectively established, and in this case, these shift valves are switched according to the vehicle speed and the throttle opening, so that, for example, a shift characteristic as shown in FIG. 4 is obtained. is known.

(Problem to be Solved by the Invention) In the above, when shifting between 2nd and 3rd gears that are adjacent to each other in the sequence of gears, or when shifting between 3rd and 4th gears, the transmission system on the disengagement side is The draining of oil from the hydraulic engagement element and the supply of oil to the hydraulic engagement element of the transmission system on the established side are started almost simultaneously, and smooth gear shifting can be achieved through appropriate co-engagement.

By the way, depending on the setting of the shift characteristics, if the throttle opening is suddenly changed, a direct shift may be performed between 2nd and 4th gears. For example, in Fig. 4, when the vehicle is running at a If the throttle opening degree is suddenly decreased from A to 8 while the gear is in progress, the shift will jump from 2nd gear to 4th gear and jump over 3rd gear. Oil supply to the mating elements starts, and the mating mesh becomes smaller, making it easier for the engine to rev up. This will be explained in detail based on FIG. 6, which shows oil pressure changes of each hydraulic engagement element. At time t1 when the throttle opening decreases from A to C in FIG. The 2nd shift valve is switched to the upshift side, oil draining from the 2nd speed hydraulic engagement element and oil supply to the 3rd speed hydraulic engagement element are started, and then the throttle opening is reduced to D at time t2 At 3
The third shift valve for speed-to-fourth speed shifting is switched to the upshift side, draining oil from the third-speed hydraulic engagement element and replenishing the fourth-speed hydraulic engagement element; in this case. When the throttle opening is suddenly reduced as described above, the oil pressure P3 of the 3rd speed hydraulic engagement element increases, and oil drainage from the element starts before the element has an engagement force, causing the oil pressure of the 2nd speed hydraulic engagement element to increase. A direct upshift from 2nd speed to 4th speed is performed by releasing the 2nd speed transmission system due to the drop in the oil pressure P2 and establishing the 4th speed transmission system due to the increase in the oil pressure P4 of the 4th speed hydraulic engagement element.

In this case, since there is a slight time difference between tl and [2], the pressure increase of P4 is delayed, and at the time when P2 drops to a value that substantially disengages the second-speed hydraulic engagement element. The 4th speed hydraulic engagement element does not have sufficient engagement force, that is, the joint engagement of both hydraulic engagement elements becomes small, causing the engine to temporarily become unloaded and causing the engine to rev up as described above. .

The present invention provides a transmission system between the low speed and high speed transmission systems that skips the medium speed transmission system among the low speed, medium speed, and high speed transmission systems according to the sequence of gears such as the above-mentioned 2nd, 3rd, and 4th speeds. It is an object of the present invention to provide a device which solves the above-mentioned problems by allowing a speed change to be performed via a medium speed transmission system even under conditions where a direct speed change is performed.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides oil supply and drainage to each hydraulic engagement element that establishes each of the low-speed, medium-speed, and high-speed transmission systems provided in the transmission. Each transmission system is selectively controlled by a shift valve that changes speed between a low-speed transmission system and a medium-speed transmission system, and a shift valve that changes speed between a medium-speed transmission system and a high-speed transmission system. In such a system, when changing speed from one of the low-speed transmission system and the high-speed transmission system to the other, the system operates until the hydraulic pressure of the hydraulic engagement element that establishes the one transmission system drops to a predetermined value. The present invention is characterized in that a shift prevention device is provided that prevents a shift valve that changes speed between the other transmission system and the medium-speed transmission system from switching to the side that establishes the other transmission system.

(Example) The present invention will be explained with reference to the illustrated embodiments.

In FIG. 1, (1) shows a transmission that performs four forward speeds and one reverse speed, and the transmission (1) is connected to an input shaft (1a ) and an output shaft (1b) connected to the drive wheels (4) of the vehicle via a differential gear (5), each transmission system (G1) (G2) ( G3) (G4) and reverse transmission system (
GR), and each forward transmission system (G1) (G2) (
The hydraulic clutches (CI, HC2), (C3), and (C4) of 1st to 4th speeds, which are hydraulic engagement elements, are intervened in G3) and (G4).

The reverse transmission system (GR) shares the 4-speed transmission system (G4) and the 4-speed hydraulic clutch (C4), and both transmission systems (G4) (GR) are connected to the selector on the output shaft (1b). This is selectively established via gear (6).

In the drawing, (n) is a one-way clutch that intervenes in the first-speed transmission system (G1) and operates to allow over-rotation on the output shaft (1b) side.

The oil supply and drainage of each of the hydraulic clutches (CI) (C2) (C3HC4) is controlled, for example, by a hydraulic circuit shown in FIG. ), "P" for parking, "R" for reverse, "N" for neutral, "C4" for automatic shifting between 1st and 4th gears, and "C4" for automatic shifting between 1st and 3rd gears. "D!", 2
Manual valve (9) that can be switched to 6 positions (2) for speed maintenance
), a shift valve device (1G) controlled according to vehicle speed and throttle opening, and a servo valve Ov for forward/reverse switching that connects the selector gear (6) described above, and a manual valve (9). At the "04" position, the first
The oil passage (Ll) is connected to the shift valve device (second oil passage (Ll) connected to the shift valve device (10).
L2), and each hydraulic clutch (C2) (C3) (C
4) Oil is now supplied and drained.

The 1st speed hydraulic clutch (C1) is always supplied with oil via the 3rd oil path (L3) branched from the 2nd oil path ([2), and is used for 1st and 2nd speeds as described later. During gear shifting, as the 2nd speed hydraulic clutch (C2) is refueled, its engagement force is gradually strengthened, and torque is transmitted through the 2nd speed transmission system (G2) to change the rotational speed of the output shaft (1b) to 1st speed. Transmission system (
When the speed exceeds the speed determined by G1), the one-way clutch (n) automatically stops torque transmission through the first speed transmission system (G1), and smooth gear shifting is performed.

Therefore, the problem with gear shifting is the 2nd to 4th gear oil pressure due to the shift valve device aO.
(C4) This is a shift at 2nd speed or higher in which oil supply/drainage is switched between 2nd and 3rd gears.

The shift valve system @aG includes a first shift valve (101) for 1st-2nd speed shifting on the upstream side, and an intermediate 2nd-3rd gear shift valve connected to this via a fourth oil path (L4). A second shift valve (102) for shifting, and a third shift valve (10) for shifting between 3rd and 4th speeds on the downstream side connected to this via a fifth oil passage (L5).
a), and the polyvalent (1G +) (102) (
10a), a governor pressure corresponding to the vehicle speed from a governor valve (121), and a first throttle valve (13+) at the left end.
), and as the vehicle speed increases, the governor pressure first causes the first shift valve (1(h) to switch from the 1st gear position on the right side to the 2nd gear position on the left side. The second oil passage (L2) is operated, and the second oil passage (L2) becomes the fourth oil passage (L4).
) is connected to the sixth oil passage (L6) on the outflow side of the second shift valve (102), and the sixth oil passage (L6) is connected to the sixth oil passage (L6) at the "C4" position of the manual valve (9). Pressure oil from the hydraulic pressure a (8) is supplied to the 2nd speed hydraulic clutch (C2) via the 7 oil passage ([7), and the gear is shifted up from 1st to 2nd gear. When the vehicle speed further increases, the 2nd gear clutch (C2) is shifted up. The valve (102) is operated to switch from the second speed position on the right side to the third speed position on the left side, and the fourth oil passage (L4) is switched and connected from the sixth oil passage (L6) to the fifth oil passage ([5]). , the eighth on the outflow side of the third shift valve (10a)
The 3rd speed hydraulic clutch (C3) is supplied with oil via the oil passage (L8), and the 6th oil passage (L6) is connected to the first oil drain passage (LDl) via the second shift valve (1G2). When oil is drained from the 2nd speed hydraulic clutch (C2), the 2nd speed is shifted up to 3rd speed, and the vehicle speed further increases, the third shift valve (10a) shifts from the 3rd speed position on the right side to the 4th speed position on the left side. position, the fifth oil passage (L5) is switched and connected from the eighth oil passage (L8) to the ninth oil passage (L9), and the manual valve (9) is connected to the ninth oil passage (L9). The 4th speed hydraulic clutch (C4) is supplied with oil through the 10th oil passage (Llo) connected at the ``C4'' position, and the 8th oil passage (L8) is connected to the 2nd exhaust through the 3rd shift valve (103). It is connected to an oil passage (LD2) to drain oil from a third-speed hydraulic clutch (C3), and to shift up from third to fourth speed.

Also, according to the deceleration, the third shift valve (10g) is
After returning to the speed position, the ninth oil passage (L9) connects to the third oil drain passage (LD3) via the third shift valve (10a), and the eighth oil passage (L8) connects to the fifth oil passage as described above. connected to the road ([5),
Oil is drained from the 4th speed hydraulic clutch (C4) and refueled to the 3rd speed hydraulic clutch (C3), and the 4th speed is downshifted to the 3rd speed. When the vehicle speed further decreases, the second shift valve (1
02) returns to the 2nd gear position on the right side, and the 8th oil passage (L8)
The fourth oil passage (LD4) is connected to the fourth oil passage (LD4) via the fifth oil passage (L5) and the second shift valve (102), and the sixth oil passage ([6] is connected to the fourth oil passage (L4) as described above. The third speed hydraulic clutch (C3) is drained from the third speed hydraulic clutch (C3) and the second speed hydraulic clutch (C2) is refilled with oil so that the third speed is downshifted from the second speed to the second speed. It is now possible to obtain the following shifting characteristics. 4th t ['

In the drawing, G is a regulator valve (151) (152) that regulates the hydraulic pressure supplied from the hydraulic source (8) to a constant line pressure.
(153) is each hydraulic clutch (C2) for 2nd to 4th speed
(C3) The accumulators connected to the seventh oil passage (E7), the eighth oil passage (E8), and the tenth oil passage (LIO) connected to (C4) are shown, and each accumulator (Is 1) (
152) (1s a) and the second throttle valve (13
The throttle pressure corresponding to the throttle opening from 2) was applied as back pressure.

The above is not particularly different from the conventional device described above, and as it is, for example, as shown in Fig. 4, by rapidly reducing the throttle opening from A to 8 while the vehicle is running in 2nd gear at a vehicle speed of VO, it is possible to directly shift from 2nd gear to 4th gear. When a situation occurs that causes an upshift, the 2nd speed hydraulic clutch (C2) is closed due to the time difference in the upshift operation between the second shift valve (102) and the third shift valve (103) as described above. Due to the delay in the start of refueling to the 4th speed hydraulic clutch (C4) with respect to the start of oil draining from the engine, the mutual engagement of both clutches (C2) and (C4) becomes small, causing the engine to temporarily go into a no-load state, causing engine engine to rev up. It becomes easier.

It should be noted that a slight engine revving during downshifting is advantageous because it reduces the difference in rotational speed between the input and output members of the hydraulic clutch on the engaging side. If you suddenly shift down from 4th gear to 2nd gear by rapidly increasing the speed from B to A, the engine will overheat due to the delay in the start of oil replenishment to the 2nd gear hydraulic clutch (C2) compared to the start of oil drain from the 4th gear hydraulic clutch (C4). This is not desirable as it may blow up.

Therefore, in the illustrated embodiment, in order to cope with both an upshift from 2nd speed to 4th speed and a downshift from 4th speed to 2nd speed, when upshifting from 2nd speed to 4th speed,
Hydraulic pressure of 2nd speed hydraulic clutch (C2) (hereinafter referred to as P2)
The third shift valve (4 of 1G) is closed until the
The first shift prevention device ae prevents the switching operation to the 4th gear position to establish the quick transmission system (G4), and the hydraulic pressure of the 4th gear hydraulic clutch (C4) (hereinafter referred to as P4) when downshifting from 4th gear to 2nd gear. A second shift prevention device Ω is provided to prevent the second shift valve (10i) from switching to the second speed, which establishes the second speed transmission system (G2) until the second shift valve (10i) decreases to a predetermined value. I took it as a thing.

To explain this in more detail, in the illustrated one, the first shift blocking device @ae is connected to the governor valve (+21) at the "D4" position of the manual valve (9), and the third shift valve (10a
) to input the governor pressure from the governor valve (13) to the governor valve (11).
It shall consist of a control valve (16a) interposed in an oil passage (111), and one end of the control valve (16a), that is, an oil chamber (16b) at the right end in the drawing, is branched from a sixth oil passage ([6)]. When P2 is input through the twelfth oil passage (L12), and P2 is equal to or greater than a predetermined value, the control valve (16a) is activated by the left end spring (
16C) from the open position on the right side to the closed position on the left side, the input of governor pressure to the third shift valve (10a) is cut off, and even if the throttle opening is decreased, the third shift valve (10a) (10a) The switching operation to the 4th speed position on the left side is prevented.

Further, the second shift prevention device (2) is configured to prevent the first throttle valve (
A control valve (17
a), and a ninth oil passage (L9) is connected to one end of the control valve (17a), that is, the oil chamber (17b) at the left end in the drawing.
P4 is input via the 14th oil passage (L14) branched from the control valve (17a) when P4 is greater than or equal to a predetermined value.
is moved from the open position on the left side to the closed position on the right side against the right end spring (17C), the input of throttle pressure to the second shift valve (102) is cut off, and the throttle opening is increased. The switching operation of the second shift valve (102) to the second speed position on the right side is prevented.

(Function) To explain the function of the present invention based on the above embodiment, the fourth
In the figure, when the throttle opening is suddenly decreased from A to 8 while the vehicle is running in 2nd gear at a vehicle speed vO, the first point at which the throttle opening decreases to C [at I, the second shift valve for 2nd-3rd gear shifting ( 102) is switched from the 2nd speed position to the 3rd speed position, oil draining from the 2nd speed hydraulic clutch (C2) and oil supply to the 3rd speed hydraulic clutch (C3) are started, as shown in FIG.
As P2 begins to fall, the oil pressure (hereinafter referred to as P3) of the third-speed hydraulic clutch (C3) begins to rise.

Here, in the conventional device described above, the third shift valve (10a) is operated to switch from the 3rd gear position to the 4th gear position at time t2 when the throttle opening degree decreases to D, and as shown in FIG.
However, according to the present invention, oil drainage from the clutch (C3) starts before the pressure is increased to a value that generates the engagement force of the third-speed hydraulic clutch (C3). However, according to the present invention, the shift prevention device @11e operates When the switching operation of the third shift valve (10a) at the second point in time is blocked, P2 decreases to a predetermined value Pa, and the operation of the device tae is released, that is, t7fiJm constituting the device tae. At time t3 when the valve (16a) is returned to the open position by the spring (16C), the third shift valve (10a) is given a switching operation to the 4th speed position, and at the time t3, P3 is as shown in the fifth figure. The pressure is sufficiently increased to shift from the 2nd speed transmission system (G2) to the 3rd speed transmission system (G3), and then the 3rd speed transmission system (G3) changes to the 4th speed transmission system by lowering P3 and increasing P4. A shift to (G4) is performed, and thus a smooth shift is performed without causing the engine to rev up, similar to the normal upshifting from 2nd speed to 3rd speed to 4th speed.

Also, if the throttle opening is suddenly increased from 8 to A while the vehicle is traveling at a vehicle speed vO, the second shift prevention device t(1?
), even if the throttle opening increases to C, the switching operation of the second shift valve (102) to the 2nd speed position is prevented unless P4 decreases to a predetermined value, and in this case, as in the above case, the 3rd speed transmission system (G3) to prevent the engine from revving up excessively as described above when a direct downshift from 4th speed to 2nd speed is performed.

In the above embodiment, there are cases in which 22 falls relatively quickly during upshifts and the shift blocking device ae is deactivated early, and cases in which 24 descends relatively quickly during downshifts cause the shift blocking device ae to be released early. F (If 171 is deactivated early, these multi-equipment @Ge
(17) Control valves (16a) (17a)
As shown in Fig. 3, an accumulator ■ is connected to each oil path (L12) (L14) that inputs 22 and P4 to the first
) The second shift prevention device (17) may be omitted if the engine does not rev up excessively even when directly downshifting from 4th gear to 2nd gear. good.

Above, 2nd speed, 3rd speed, 4th speed transmission system (G2) (G3) (G
4) has been described with reference to an embodiment in which the present invention is applied as a low-speed, medium-speed, and high-speed transmission system, respectively. However, the present invention is not limited to this. For example, the present invention is applicable to a five-speed transmission system, in which the transmission system changes from 3rd to 5th speed. If there is a possibility that a direct upshift may occur, a shift prevention device prevents the switching operation of the shift valve for 4th to 5th speed shifting to the 5th speed side until P3 decreases to a predetermined value. will be established.

Furthermore, the present invention is of course applicable to transmissions using planetary gear mechanisms, which are equipped with hydraulic engagement elements such as hydraulic brakes other than hydraulic clutches.

(Effects of the Invention) As described above, according to the present invention, even under conditions where a direct speed change from one of the low-speed transmission system and the high-speed transmission system to the other is performed, the hydraulic pressure of the low-speed transmission system and the high-speed transmission system can be changed. Until the hydraulic pressure of the mating element drops to a predetermined value, the shift valve that changes gears between the other transmission system and the medium-speed transmission system is held in a state that establishes the medium-speed transmission system by the shift prevention device, and normally As in the case of the speed change, the speed is smoothly changed via the medium speed transmission system, and the above-mentioned disadvantages of the conventional device do not occur.

[Brief explanation of the drawing]

Fig. 1 is a line diagram of an example of a transmission to which the device of the present invention is applied, Fig. 2 is a hydraulic circuit diagram thereof, Fig. 3 is a hydraulic circuit diagram showing a modification thereof, and Fig. 4 is a line diagram showing transmission characteristics. Figure 5 is a diagram showing the hydraulic pressure change of the hydraulic engagement element when shifting from 2nd to 4th gear, and Fig. 6 is a diagram showing the hydraulic pressure change of the hydraulic engagement element when shifting from 2nd to 4th gear in a conventional device. FIG. 3 is a diagram showing changes in oil pressure. (1)...Transmission (G2)...2-speed transmission system (low-speed transmission system) (G3)...
・3-speed transmission system (medium-speed transmission system) (G4)...4-speed transmission system (high-speed transmission system) (C2) (C3) (C4)...hydraulic clutch (hydraulic engagement element) (102) ...Second shift valve (shift valve for shifting between the low-speed transmission system and medium-speed transmission system) (103)...Third shift valve (for shifting between the medium-speed transmission system and the high-speed transmission system) shift valve) aeΩ...
Shift prevention device @2 Figure 1 Figure 5 @ Figure 4 2

Claims (1)

[Claims] A shift valve that changes speed between the low-speed transmission system and the medium-speed transmission system, and a medium-speed In a system in which each transmission system is selectively established by switching control using a shift valve that changes speed between the transmission system and the high-speed transmission system, switching from one of the low-speed transmission system and the high-speed transmission system to the other a shift valve that operates until the hydraulic pressure of a hydraulic engagement element that establishes the one transmission system drops to a predetermined value when shifting gears between the other transmission system and the medium-speed transmission system; A control device for a hydraulically actuated transmission for a vehicle, characterized in that a shift prevention device is provided for preventing a switching operation to the side that establishes the other transmission system.