JPH03213723A - Multiple disc clutch lubricating mechanism for automatic transmission - Google Patents

Abstract

PURPOSE:To suppress drag torque by providing a clutch drum rotated around a specified shaft, two plate groups, and the like, as well as forming a lubricating oil nozzle at a supporting member, and opening/closing the nozzle by the movement of the second plate group. CONSTITUTION:In the speed change state requiring the engagement of a multiple disc clutch 32, a valve is opened to lead operating oil into a hydraulic chamber P from an operating oil input port 28. When the pressure in the hydraulic chamber P rises and piston pressing force exceeds the energizing force of a return spring 31, a clutch piston 30 starts its movement. The clutch 32 is pushed by this piston 30, and the retaining plate 35 of the clutch 32 is compressively deformed, so that a first and a second plate groups 33, 34 are moved in the axial direction L and simultaneously their frictional faces are mutually slided to start initial engagement. When the plate group 34 of the clutch 32 is moved by the operation of the piston 30, communicating passages 36-39 formed at a ring gear 22 are opened to feed lubricating oil to the clutch 32 so as to suppress the generation of heat.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a multi-disc clutch lubrication mechanism for an automatic transmission used in a vehicle, and in particular improves the cooling performance of a wet multi-disc clutch during an engagement transition period. The present invention also relates to a multi-disc clutch lubrication mechanism for an automatic transmission intended to suppress drag torque during disengagement.

(Prior art) In an automatic transmission that increases or decreases engine torque using a multi-disc clutch, planetary gear, etc. and converts it into an appropriate drive torque depending on the driving condition, the multi-disc clutch generally slides during the transition period of engagement. Kinetic frictional heat is generated.

In particular, automatic transmissions applied to high-output engines transmit a large amount of torque and therefore generate a considerable amount of heat, which can lead to various problems such as deterioration of the automatic transmission oil. .

Figure 18 is a detailed diagram of the main parts of a conventional automatic transmission.
The main parts near two multi-disc clutches (low clutch as an example) are shown. In this figure, 10 is a wet type multi-disc clutch, and the multi-disc clutch 10 has a clutch drum 11.
It has a first plate group 12 that engages with the ring gear 13 and a second plate group 14 that engages with the ring gear 13. When the clutch piston 15 operates, both plate groups 12 and 14 are frictionally engaged, and the clutch drum 11 The structure allows torque transmission between the ring gear 13 and the ring gear 13.

The amount of heat Q generated during the engagement transition period of the multi-disc clutch IO is proportional to the product (TxR) of the transmission torque T and the slipping rotation speed R.

Therefore, during the engagement transition period when transmitting a large torque, the amount of heat generated becomes considerably large to the extent that it cannot be ignored.

Therefore, in the conventional automatic transmission shown in FIG. 17, an oil hole 16 is formed in the ring gear 13.

In this way, the lubricating oil that has entered the inside of the planetary gears including the ring gear 13 is forced to jet out from the oil holes 16 due to the centrifugal force of the planetary gears, and the multi-disc clutch 10 can be cooled.

As shown in the graph of FIG. 19, the cooling capacity increases as the amount of lubricating oil supplied increases, so the cooling effect can be enhanced during high rotations when the centrifugal force of the planetary gear is large.

(Problem B to be Solved by the Invention) However, in the conventional multi-disc clutch lubrication mechanism of an automatic transmission, the oil hole 16 always remains open, so that when the multi-disc clutch IO is disengaged, There is a problem to be solved in terms of suppressing the drag torque in the

That is, the multi-plate clutch IO is engaged or disengaged as the automatic transmission changes gears, but if lubricating oil is supplied through the oil holes 16 even when the multi-plate clutch IO is not engaged, the first plate group 12
The viscous resistance of the lubricating oil acts between the friction surfaces of the plate group 14 and the second plate group 14, and this causes drag torque
rque (nidrag torque) is generated.

However, as shown in the graph of Fig. 20 showing the relationship between the amount of lubricating oil supplied and the drag torque, the drag torque increases as the amount of lubricating oil from the oil hole 16 increases, that is, at high rotations where the centrifugal force of the planetary gear is large. It tends to increase over time, so if you try to increase the amount of lubricant to improve the cooling effect,
There was also a problem with the drag torque increasing.

(Object of the invention) The present invention was made in view of the above problems, and
The purpose is to suppress drag torque while maintaining cooling performance by supplying lubricating oil only during the engagement transition period of the multi-disc clutch.

(Means for Solving the Problem) Claim 1 of the present invention provides a clutch drum that rotates around a predetermined axis, a first plate group that engages with the inner surface of the drum and is movable in the axial direction, a second plate group interposed between the plates of the first plate group; and a support member supporting the second plate group while allowing movement in the axial direction; A lubricating oil spout is formed, and the spout is configured to be able to be opened and closed as the second plate group moves. A clutch piston with a wet multi-plate clutch disposed on the other side forms an oil passage communicating from one side of the clutch piston to the other side, and when the pressure in the hydraulic chamber increases, the oil passage is closed. Further, claim 3 of the present invention provides a lubricating oil discharge port facing the wet type multi-disc clutch, and an electromagnetic interrupter interposed between the discharge port and the lubricating oil supply source. The present invention is characterized by comprising a valve and a control means for operating an electromagnetic cutoff valve during a transition period of frictional engagement of the multi-disc clutch.

(Function) According to claim 1 of the present invention, the ejection port is opened and closed as the second plate group moves. Therefore, if it is possible to close the jet nozzle at the position of the second plate group when it is not engaged, the jet nozzle will open when it is engaged, which will provide a cooling effect when it is engaged and suppress the drag torque when it is not engaged. It is possible to achieve both effectiveness and effectiveness.

Further, in claim 2 of the present invention, in order to engage the multi-disc clutch, when the pressure in the hydraulic chamber is increased from zero,
During the rising transition period, lubricating oil is supplied to the multi-disc clutch via the oil passage, and when a predetermined pressure is reached, the supply is cut off. Therefore, since the pressure in the hydraulic chamber is zero during disengagement, generation of drag torque during disengagement is avoided, while lubricating oil is supplied during the transition period of engagement to provide a sufficient cooling effect.

Further, in claim 3 of the present invention, the electromagnetic cutoff valve is opened only during the transition period of engagement of the multi-disc clutch, and lubricating oil is supplied only at an appropriate time when heat generation becomes a problem. Therefore, the drag torque at the time of disengagement can be suppressed while maintaining the cooling effect.

(Example) Hereinafter, the present invention will be explained based on the drawings.

1 to 3 are diagrams showing a first embodiment of the present invention, and are diagrams showing an embodiment of a multi-disc clutch lubrication mechanism for an automatic transmission according to a first aspect.

First, the configuration will be explained. In FIG. 1, 20 is a planetary gear including a sun gear 21, a ring gear 22, a pinion gear 23, etc., 24 is an input shaft forming a lubricating oil passage 25 in the shaft, 26 is an output shaft, 27
28 is a hydraulic oil input port into which clutch hydraulic oil is appropriately input; 29 is a clutch drum that rotates around a predetermined axis (L); 30 is a clutch piston;
1 is a return spring that urges the clutch piston 30 to the initial position (the position shown), and 32 is a multi-disc clutch.

The multi-plate clutch 32 functions as a low clutch, for example,
The structure includes a first plate group 33 (also referred to as a driven plate), a second plate group 34 (also referred to as a drive plate), and a retaining plate 35, and the first plate group 33 is attached to the clutch drum 29 so as to be movable in the axial direction. At the same time, the second plate group 34 is engaged with the ring gear 22 so as to be movable in the axial direction. The ring gear 22 functions as a support member that supports the second plate group 34 while allowing movement in the axial direction.

The first plate group 33 and the second plate group 34 are in the position shown in the figure due to the elastic force of the retaining plate 35 when the flange piston 30 is in the initial position. When hydraulic oil is introduced into the chamber P and the clutch piston 30 moves in the axial direction against the biasing force of the return spring 31, the retaining plate 35 moves while being compressed and deformed, so that they frictionally engage with each other. It has become. .

36 to 39 are communication passages 36 to 39, for example, cylindrical, formed in the ring gear 22; one end side grooves 36a to 39a of the communication passages 36 to 39 are formed on the gear surface of the ring gear 22; The openings 36b to 39b are directed toward the inside of the planetary gear 20. Here, one end side opening hole 36 of the communication passages 36 to 39
a to 39a function as lubricating oil spouts, and their positions (1
) and the opening diameter (II) are (1) when the position of the second plate group 34 is in the above (■), the second plate group 34 is arranged at a position that coincides with each plate end of this second plate group 34; (n) the second plate The opening diameter D is set to be slightly smaller than the thickness d of each plate end of the group 34 (d≧D).

Next, the effect will be explained.

(a) In the case of a gear change state that requires engagement of the multi-disc clutch 32, when a valve (not shown) is opened and hydraulic oil is introduced from the hydraulic oil input port 28 into the hydraulic chamber P, the pressure in the hydraulic chamber P increases. However, when the piston pressing force exceeds the urging force of the return spring 31, the clutch piston 30 begins to move. Then, the multi-plate clutch 32 is pushed by the clutch piston 30, the retaining plate 35 of the multi-plate clutch 32 is compressed and deformed, and the first plate group 33 and the second plate group 34 are moved in the axial direction. Initial locking begins by sliding both friction surfaces against each other. Incidentally, a state diagram at this time is shown in FIG.

As mentioned above, during this transitional period of engagement, a heat amount Q proportional to the product (TxR) of the transmission torque T and the slipping rotation speed R is generated, which is a problem. When the second plate group 34 of the multi-disc clutch 32 moves due to the operation of Oil can be supplied to the multi-disc clutch 32 via the communication passages 36 to 39, and heat generation Q during the engagement transition period can be suppressed.

(b) On the other hand, in the case of a gear change state that does not require engagement of the multi-plate clutch 32, a valve not shown is closed, the pressure in the hydraulic chamber P is set to zero, and the first plate group 33 and the second plate group 34 are closed.
However, at this time, the second plate group 34
is at the initial position (
Since the plate end of the second plate group 34 is returned to the position shown in FIG.
6a to 39a are closed.

Therefore, since no lubricating oil is supplied when the multi-plate clutch 32 is disengaged, the viscous resistance acting between the friction surfaces of the first plate group 33 and the second plate group 34 can be made as small as the residual lubricating oil. drag torque
ue drag torque) can be suppressed.

As described above, according to this embodiment, the ring gear 22
The communication passages 36 to 39 formed in the clutch piston 30
Since it is constructed so that it can be opened and closed by the movement of the second plate group 34 in conjunction with the activation/deactivation of As a result, it is possible to suppress the drag torque when the multi-disc clutch 32 is not engaged while obtaining a cooling effect during the transition period of engagement.

4 to 8 are diagrams showing a second embodiment of the present invention, and are diagrams showing an embodiment of a multi-disc clutch lubrication mechanism for an automatic transmission according to claim 2.

In Fig. 4 and Fig. 5 showing details of the main parts of Fig. 4,
40 is the automatic transmission case, 41 is the clutch piston,
42 is a return spring, 43 is an oil seal, and the clutch piston 41 has one side 41a facing the hydraulic chamber 44 and the other side 4 facing the wet multi-disc clutch 45.
An oil passage 46 communicating with the oil passage 1b is formed, and a valve mechanism (closing means) 47 that can close a circular opening 46a of the oil passage 46 is attached to one side 41a.

FIG. 6 is a detailed view of the valve mechanism 47. The valve mechanism 47 consists of a plate spring 47a and a conical needle valve 47b attached to one end of the plate spring 47a.
The other end is fixed to one side surface 41a of the clutch piston 41 with a rivet 47c, and the needle valve 47b and the opening 46a of the oil passage 46 are made to face each other, and the spring force of the temporary spring 47a is used to connect the opening 46a with the needle valve 47b. Needle valve 4
7b is slightly spaced apart.

In such a configuration, when hydraulic oil for clutch engagement is supplied to the hydraulic chamber 44 and the pressure in the hydraulic chamber 44 (clutch engagement pressure) is increased, (a) immediately after the pressure rises, (b)
The following effects are obtained during the pressure increase transition period and (iii) maximum pressure.

(a) In FIG. 7(a), since the pressure increase in the hydraulic chamber 44 is at an extreme value, the plate spring 47a is not deformed, and the gap between the opening 46a and the needle valve 47b and the oil passage are A small amount of the hydraulic oil in the hydraulic chamber 44 is supplied to the multi-disc clutch 45 through the multi-disc clutch 46 .

(b) In FIG. 7(b), when the pressure in the hydraulic chamber 44 increases, the temporary spring 47a begins to deform, and with this deformation, the needle valve 47b approaches the opening 46a. At this time, the gap between the opening 46a and the needle valve 47b is maintained, and a large amount of the pressurized hydraulic oil in the hydraulic chamber 44 is supplied to the hydraulic chamber 44 through the oil passage 46.

(c) In FIG. 7(C), when the pressure in the hydraulic chamber 44 reaches the maximum and the multi-plate clutch 45 is engaged, the plate spring 47a
is sufficiently deformed, the needle valve 47b is seated in the opening 46a, and the opening 46a is completely closed.

That is, in FIG. 8, which shows the change in the internal pressure of the hydraulic chamber 44 when the clutch engagement signal (signal for operating the clutch engagement pressure valve not shown) changes from off (non-operation) to on (operation), the pressure inside the hydraulic chamber 44 changes. The internal pressure increases slightly immediately after the clutch engagement pressure signal changes from OFF to ON (V 1 ),
At this time, some hydraulic oil passes through the oil passage 46, and
While the internal pressure continues to rise (■2), the hydraulic oil passing through the oil passage 46 also increases, and when the internal pressure reaches the maximum value (max), the oil passage 46 is closed and the passage of hydraulic oil becomes zero. Become.

As described above, in this embodiment, the oil passage 46 is released during the transition period of engagement, and the effect of supplying hydraulic oil to the multi-disc clutch 45 and suppressing its heat generation is obtained. 45 is not engaged, the hydraulic oil is not normally supplied to the hydraulic chamber 44, so the multi-disc clutch 45 is also not supplied with hydraulic oil, which has the effect of suppressing the drag torque of the multi-disc clutch 45. You can get it together.

Furthermore, when the connection is made, the oil passage 46 is closed and the hydraulic chamber 44 is closed.
It is possible to prevent pressure loss within the oil pump, and also to reduce the power loss of the oil pump.

9 to 12 are diagrams showing a third embodiment of the present invention, and are diagrams showing an embodiment of a multi-disc clutch lubrication mechanism for an automatic transmission according to claim 3.

In FIG. 9, 50 is a clutch piston, 51 is a return spring, 52 is a wet multi-disc clutch, and 53 is a clutch drum. The clutch drum 53 is formed with a port 54 as a lubricating oil discharge port. One end of the port 54 communicates with the electromagnetic switching valve 55, and the other end is open so as to face the multi-disc clutch 52.

The electromagnetic switching valve 55 functions as an electromagnetic cutoff valve, and switches the oil passage from the closed state to the open state in response to the switching signal S1 from the signal generation circuit 56. When the electromagnetic switching valve 55 is in the open state, the lubricating oil pressure generation source (the shown path) lubricating oil from the port 54 is supplied to the port 54.

The signal generation circuit 56 functions as a control means and is a range detection circuit 57 (for example, an inhibitor switch) of an automatic transmission.
(If the multi-disc clutch 52 is a low & reverse brake, the range signal or the R range signal) is received, a predetermined time (t) from the time of reception,
Continue outputting the switching signal S1. The predetermined time (1) corresponds to the engagement transition time of the multi-disc clutch 52.

Next, the effect will be explained. In the operation sequence diagram of FIG. 10, first, a range signal from the range detection circuit 57 is read (step P1), and switching to, for example, the ■ range or the R range is determined (step P2).

If there is switching (YES command), output the switching signal S1 (step P3), switch the electromagnetic switching valve 55 to the open state, and detect the end of gear shifting (step P4), or
When the elapse of a predetermined time (1) is detected, the output of the switching signal S1 is stopped (step P5), and the electromagnetic switching valve 55 is switched to the closed state.

Therefore, as shown in the timing chart of FIG. 11, a period of time (1
), the switching signal S1 can be output to open the electromagnetic switching valve 55, and during this time, lubricating oil can be supplied to the multi-disc clutch 52 via the port 54. As a result, lubricating oil can be supplied only during the transient period of engagement of the multi-disc clutch 52, where heat generation is a problem, and lubricating oil supply is prohibited both when the clutch is not engaged and when it is fully engaged, and the drag torque is increased when the clutch is not engaged. It is possible to reduce oil pump (lubricating oil generation source) loss during suppression (see FIG. 12) and full engagement.

It is also conceivable to form an orifice passage 61 in the clutch piston 60, as shown in FIGS. 13 to 16. That is, in FIG. 13, the clutch piston 60
An orifice passage 61 having a length Ll and an inner diameter d1 is formed by penetrating both sides of the hole. The orifice passage 61 has an open end 61 a of the hydraulic chamber 62 on the inner peripheral side of the clutch piston 60 and an open end 61 b on the multi-disc clutch 63 side as the clutch piston 60 .
Place it on the outer periphery side. Also, the relationship between Ll and dl is (
It is desirable that L L /d 1 >10).

In this way, the hydraulic oil in the hydraulic chamber 62 is caused by the rotational centrifugal force of the clutch piston 60 to flow into the orifice passage 61.
Since the water is supplied to the multi-disc clutch 63 from the above, an effect of cooling the multi-disc clutch 63 can be obtained.

By the way, since the amount of heat generated by the multi-disc clutch 63 is small when starting a vehicle where the hydraulic oil temperature is low (or when the load is low and the rotation speed is low), the multi-disc clutch 63 is not activated from the viewpoint of reducing oil pump loss. It is preferable not to supply oil. In this embodiment, when the viscosity of the hydraulic oil is high (generally, the viscosity is high at low load, low rotation, or low temperature), the amount of oil passing through the orifice passage 61 is limited, so oil pump loss can be reduced. .

That is, the amount of hydraulic oil passing through the orifice passage 61 is
As shown in FIG. 14, it increases as the oil temperature increases ((a)), as the internal pressure of the hydraulic chamber 62 increases ((b)), or as the rotation of the clutch piston 60 increases. (C) of the same figure.

Therefore, under high load, high rotation, or high oil temperature, when the friction material of the multi-disc clutch 63 is likely to burn out, as shown in FIG.
As shown in FIG. 2, sufficient hydraulic oil can be supplied to the multi-disc clutch 63 to prevent burnout, and at low temperatures, low rotations, or low loads, the amount of orifice oil can be reduced to reduce oil pump loss.

Note that this embodiment can also be modified as shown in FIGS. 15 and 16. That is, in FIG. 15, if an oil well 75 is formed in the inner peripheral part of the drive plate 74 that constitutes the multi-disc clutch 73, the hydraulic oil from the orifice passage 61 can be evenly distributed to the multi-disc clutch 73. . In addition, in FIG. 16, a communication port 81 is formed in the clutch piston 80, and a solid member 8 is formed inside the communication port 81.
2 is inserted, and the gap between the inner wall of the communication port 81 and the outer wall of the solid member 82 is used as an orifice passage. Solid member 8
Various cross-sectional shapes can be considered as exemplified in FIGS. 17(a) to 17(C). In this way, the orifice passage can be created by simple machining, and the assembly can be easily performed.

(Effects) According to the present invention, lubricating oil can be supplied only during the engagement transition period of the multi-disc clutch, and drag torque can be suppressed while maintaining cooling performance.

[Brief explanation of drawings]

1 to 3 are diagrams showing a first embodiment of a multi-disc clutch lubrication mechanism for an automatic transmission according to the present invention, FIG. 1 is a configuration diagram thereof, and FIG. 2 is a diagram of its operating state when engaged. , FIG. 3 is a graph showing the amount of lubricating oil when the lubricant is engaged and when it is not engaged. Fourth
8 are diagrams showing a second embodiment of the multi-plate clutch lubrication mechanism for an automatic transmission according to the present invention, FIG. 4 is a configuration diagram thereof, FIG. 5 is a configuration diagram of its main parts, and FIG. 6 is a detailed view of the valve mechanism, and Fig. 7 Ca) to (C) are images immediately after the start of the engagement.
Diagrams explaining the effects during the engagement transition period and at the completion of engagement,
FIG. 8 is a timing chart of FIG. 7. 9th to 1st
FIG. 2 is a diagram showing a third embodiment of the multi-disc clutch lubrication mechanism for an automatic transmission according to the present invention, and FIG. 9 is a configuration diagram thereof;
FIG. 10 is an operation sequence diagram, FIG. 11 is a timing chart, and FIG. 12 is a graph showing the drag torque reduction effect. 13 to 17 are diagrams showing other preferred embodiments; FIG. 13 is a configuration diagram thereof, FIGS. 14(a) to (d) are graphs for explaining its operation, and FIG. 15 is its Another preferred configuration diagram, FIG. 16, is another preferred configuration diagram, and FIGS. 17(a) to (C) are diagrams illustrating the cross-sectional shape of the solid member, respectively. 1st
Figures 8 to 20 are diagrams showing a conventional multi-disc clutch lubrication mechanism for an automatic transmission, Figure 18 is its configuration diagram, Figure 19 is a graph showing the relationship between the amount of lubricating oil supplied and the cooling capacity, and Figure 2
FIG. 0 is a diagram showing the relationship between the amount of lubricating oil supplied and the drag torque. 22...Ring gear (support member), 29...
... Taranochi drum, 33... First plate group, 34... Second plate group, 36a to 39a... One end side opening (lubricating oil spout) 41... ...Clutch piston, 41a...One side, 41b...Other side, 44...Hydraulic chamber, 45...Wet type multi-disc clutch, 46 ... Oil passage, 47 ... Pulp mechanism (closing means), 52 ...
...Wet type multi-disc clutch, 54...Port (lubricating oil discharge boat), 55.
...Solenoid switching valve (electromagnetic cutoff valve), 56...
- Signal generation circuit (control means).

Claims (1)

[Scope of Claims] 1) A clutch drum that rotates around a predetermined axis, a first plate group that engages with the inner surface of the drum and is movable in the axial direction, and between each plate of the first plate group. a second plate group interposed therein; and a supporting member supporting the second plate group while allowing movement in the axial direction, at least one lubricating oil spout being formed in the supporting member, A multi-plate clutch lubrication mechanism for an automatic transmission, characterized in that the jet outlet can be opened and closed as the second plate group moves. 2) A clutch piston defining a hydraulic chamber on one side and arranging a wet multi-disc clutch on the other side;
Multi-plate clutch lubrication for an automatic transmission, characterized by forming an oil passage communicating from one side of the clutch piston to the other side, and providing a closing means for closing the oil passage when the pressure in the hydraulic chamber increases. mechanism. 3) A lubricating oil discharge port facing the wet multi-disc clutch, an electromagnetic cutoff valve interposed between the discharge port and the lubricating oil supply source, and control for operating the electromagnetic cutoff valve during the transition period of friction engagement of the multi-disc clutch. A multi-plate clutch lubrication mechanism for an automatic transmission, characterized by comprising means.