KR20180067295A - Oil pump for automatic transmission - Google Patents

Abstract

Disclosed is an oil supply device for an automatic transmission. According to an embodiment of the present invention, the oil supply device for an automatic transmission includes: an oil pump for generating a hydraulic pressure while an internal gear connected to an output shaft of an engine, which is engaged with an external gear intermeshed in a case having an inlet port and an outlet port, is rotated; an accumulator connected to a discharge side of the oil pump through a hydraulic line to charge the oil pressure generated by the oil pump; a clutch provided between the inner gear of the oil pump and the output shaft of the engine to control the power of the engine transmitted to the inner gear using the oil pressure of the accumulator as a control pressure; and a piston valve provided on a control pressure line connecting the accumulator and the clutch to control the control pressure supplied to the clutch along the control pressure line in accordance with a charging hydraulic pressure of the accumulator while being switched on or off.

Description

Technical Field [0001] The present invention relates to an oil supply apparatus for an automatic transmission,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an oil supply apparatus for an automatic transmission, and more particularly, to an oil supply apparatus for an automatic transmission that efficiently controls engine power transmitted to a mechanical oil pump using a clutch .

Recently, as global oil prices and emission regulations have been strengthened, automakers are eco-friendly and are concentrating on developing technologies that can improve fuel efficiency.

In order to achieve such fuel efficiency improvement goals, various studies have been actively carried out, including high-efficiency engines, high-efficiency transmissions, and body weight reduction. In the field of transmission, constant research and development is being carried out to improve fuel efficiency through double clutch transmission (DCT) and high efficiency automatic transmission (AT).

On the other hand, in most automatic transmissions and double clutch transmissions, oil pressure is used for shift control and lubrication, and oil pressure is generated by driving the oil pump, which causes a loss in this process.

That is, unnecessary consumption power of the oil pump should be minimized in order to increase the efficiency of the oil pump and thereby improve the fuel efficiency.

In this way, in order to increase the efficiency of the oil pump, a mechanical oil pump (MOP) is often replaced by an electric oil pump (EOP) in many cases.

That is, the mechanical oil pump always operates at the same speed as the RPM of the engine irrespective of the required hydraulic pressure, so that the hydraulic loss occurs. However, since the electric oil pump is driven by the motor only when the hydraulic pressure is low, This has a small advantage.

However, since the electric oil pump converts the power of the engine into electricity and drives the motor, energy conversion loss occurs, which limits the overall fuel efficiency.

An ideal oil pump is an oil pump that can operate on demand only when needed, such as an electric oil pump, with no energy conversion losses, such as a mechanical oil pump.

The embodiment of the present invention can reduce the hydraulic pressure loss of the mechanical oil pump by making it possible to connect or block the power of the engine transmitted to the mechanical oil pump by using the clutch operated according to the charged oil pressure of the accumulator, An oil supply apparatus for a transmission is provided.

Further, in the embodiment of the present invention, the hysteresis effect according to the operating angle of the valve spring is used to vary the ON / OFF operating pressure of the piston valve, thereby efficiently controlling the clutch to minimize the oil pressure loss of the mechanical oil pump. Device.

In one or more embodiments of the present invention, in an oil supply apparatus for an automatic transmission, an internal gear connected to an output shaft of an engine is connected to an external gear intermeshed inside a case having an inlet and an outlet, ; An accumulator connected to the discharge side of the oil pump through an oil line to charge the oil pressure generated by the oil pump; A clutch configured to be interposed between an inner gear of the oil pump and an output shaft of the engine and to control the power of the engine to be transmitted to the inner gear using the oil pressure of the accumulator as a control pressure; And a piston valve that is provided on a control pressure line connecting the accumulator and the clutch and which controls the control pressure supplied to the clutch along the control pressure line while being turned on and off according to a charged oil pressure of the accumulator An oil supply device for a transmission may be provided.

The oil pump may be an internal gear pump.

In addition, a check valve may be formed on the hydraulic line to prevent the charged hydraulic pressure in the accumulator from flowing back to the oil pump.

The clutch further includes a clutch case having a spline section and a hydraulic chamber formed on an inner circumferential surface of the front end of the output shaft, the clutch case being formed in a cylindrical shape and fixed to the rotational center of the inner gear, A rotating disk disposed inside the clutch case corresponding to the friction disk and spline shaft formed at the center of the top surface passes through the clutch case and spline coupled to the spline portion of the output shaft to rotate integrally with the output shaft; And a clutch spring interposed between the inner bottom surface of the clutch case and the rotating disk to provide a pressing force to frictionally couple the rotating disk to the friction disk.

The oil pressure chamber is formed as a space portion inside the spline portion on the inner peripheral surface of the front end of the output shaft so as to be supplied with the control hydraulic pressure of the accumulator, and is connected to the control pressure line through an adapter provided corresponding to the oil hole on the output shaft .

In addition, the spline shaft may be disposed at the tip corresponding to the hydraulic chamber so as to move in the axial direction according to the pressure of the hydraulic chamber.

Also, a friction pad may be provided on the rotating disc on an upper surface corresponding to the friction disc.

In addition, the piston valve may include a valve housing installed on the control line through an inlet and an outlet, and forming a spring seal at a lower portion thereof; A piston which reciprocates within the valve housing by a control pressure supplied through the control pressure line and is operated on and off while opening or closing the inlet; And a valve spring that is hinged to one side of the lower portion of the spring chamber and hinged to the lower end of the spring chamber to move within a predetermined angle range of the spring while providing an operating force to the piston toward the inlet side, Spring.

The valve housing may also have the inlet connected to the accumulator via a control line, and the outlet connected to the clutch through a control line.

The embodiment of the present invention can control the power of the engine that is transmitted to the mechanical oil pump by using a clutch that operates in accordance with the charged oil pressure of the accumulator, thereby minimizing the oil pressure loss of the oil pump, It is effective.

Further, in the embodiment of the present invention, by using the hysteresis effect according to the operating angle of the valve spring, the clutch is controlled by varying the on / off operation pressure of the piston valve so that the oil pump is driven in an on- Thereby minimizing energy conversion loss.

1 is a configuration diagram of a hydraulic pressure supply apparatus for an automatic transmission according to an embodiment of the present invention.
2 is a cross-sectional view of a clutch off state of an oil pump applied to an oil supply apparatus according to an embodiment of the present invention.
3 is a sectional view of an on state of a piston valve applied to an oil supply apparatus according to an embodiment of the present invention.
4 is a sectional view of an off state of a piston valve applied to an oil supply apparatus according to an embodiment of the present invention.
5 is a sectional view of an on state of a check valve applied to an oil supply apparatus according to an embodiment of the present invention.
6 is a cross-sectional view of an oil pump applied to an oil supply apparatus according to an embodiment of the present invention in an on-state.
7 is a sectional view of an off state of a check valve applied to the oil supply apparatus according to the embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

However, in order to clearly illustrate the embodiments of the present invention, portions not related to the description are omitted.

2 is a sectional view of a clutch off state of an oil pump applied to an oil supply apparatus according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of an oil pump of an automatic transmission according to an embodiment of the present invention, FIG. 3 is a sectional view of an on state of a piston valve applied to an oil supply apparatus according to an embodiment of the present invention, and FIG. 4 is an exploded perspective view of a piston valve applied to an oil supply apparatus according to an embodiment of the present invention. 5 is a sectional view of an on state of a check valve applied to an oil supply apparatus according to an embodiment of the present invention.

The oil supply device for an automatic transmission according to the embodiment of the present invention can be used to connect or disconnect the power of the engine transmitted to the mechanical oil pump 10 by using the clutch 30 that operates in accordance with the hydraulic pressure filled in the accumulator 20. [ The oil pressure and the energy loss are minimized by controlling the mechanical oil pump by an on demand system.

1, an oil supply apparatus for an automatic transmission according to the present invention includes an oil pump 10, an accumulator 20, a clutch 30, and a piston valve 40.

2, the oil pump 10 includes an internal gear pump. In the case 11 having the inlet H1 and the outlet H2, the internal gear 13 and the external gear 15 communicate with each other. Respectively.

The inner gear 13 rotates with respect to the outer gear 15 by a rotational power transmitted to the output shaft 50 of the engine and sucks the oil from the oil pan through the inlet H1, Thereby generating the hydraulic pressure.

1, the accumulator 20 is connected to the discharge side of the oil pump 10 through a hydraulic line L1. The accumulator 20 is charged with the oil pressure generated by the oil pump 10, (60).

Here, the hydraulic pressure consuming portion 60 may be a control portion such as a brake unit or a clutch unit requiring a high-pressure hydraulic pressure, or a lubricating portion such as a gear, a brake unit or a clutch unit requiring a large flow rate.

The clutch 30 is disposed between the inner gear 13 of the oil pump 10 and the output shaft 50 of the engine so as to control the oil pressure of the accumulator 20 to control the inner gear 13, To the engine.

2, the clutch 30 includes a spline section 51 and a hydraulic chamber 53 formed on the inner circumferential surface of the front end of the output shaft 50 and has a clutch case 31, a rotating disk 33, , And a clutch spring (35).

The oil pressure chamber 53 is formed as a space inside the spline portion 51 on the inner circumferential surface of the front end portion of the output shaft 50 so as to receive the charging hydraulic pressure of the accumulator 20 as the control pressure.

The oil pressure chamber 53 is connected to a plurality of oil holes 55 on the output shaft 50 and is connected to the oil hole 55 through an adapter 57 provided on the outer peripheral side of the output shaft 50 And is connected to the control voltage line L2.

The control pressure line L2 connects the accumulator 20 and the hydraulic chamber 53 of the clutch 30 to supply the charged hydraulic pressure of the accumulator 20 to the hydraulic chamber 53 as control pressure .

The clutch case 31 is formed in a cylindrical shape and fixed to the upper surface of the rotation center of the inner gear 13, and a friction disc 31a is formed on the inner upper surface.

At this time, the clutch case 31 is rotatably supported by the internal gear (not shown) formed inside the case 11 of the oil pump 10 while maintaining the sealing between the clutch case 31 and the case 11 of the oil pump 10 13).

The rotary disc 33 is disposed inside the clutch case 31 in correspondence with the friction disc 31a and the spline shaft 37 is integrally provided at the center of the upper surface.

The spline shaft 37 passes through the clutch case 31 and is splined to the spline portion 51 of the output shaft 50 so as to be integrally rotated with the output shaft 50.

The spline shaft 37 is disposed at the tip corresponding to the hydraulic chamber 53 so as to move in the axial direction in accordance with the pressure of the hydraulic chamber 53.

That is, the rotary disk 33 is configured to rotate integrally with the output shaft 50 together with the spline shaft 37, separately from the clutch case 31.

The rotary disc 33 is constructed such that a friction pad 33a is integrally provided on the upper surface corresponding to the friction disc 31a and is capable of frictionally contacting the friction disc 31a through the friction pad 33a.

The clutch spring 35 is interposed between the inner bottom surface of the clutch case 31 and the rotary disk 33 so that the friction pad 33a of the rotary disk 33 is engaged with the friction disk 31a So as to provide a pressing force.

The clutch spring 35 is not a member that rotates together with the rotary disc 33 but has a lower end fixed to the clutch case 31, Or may be a member that rotates together with the clutch case 31 regardless of the rotation of the rotary disc 33. [

The piston valve 40 is formed on the control pressure line L2 connecting the accumulator 20 and the hydraulic chamber 53 of the clutch 30 and is connected to the accumulator 20 in accordance with the charging hydraulic pressure of the accumulator 20 And has a function of connecting or disconnecting the control pressure supplied to the hydraulic chamber (53) of the clutch (30) along the control pressure line (L2) while operating on and off.

Referring to FIG. 3, the piston valve 40 includes a valve housing 41, a piston 43, and a valve spring 45.

The valve housing 41 is installed on the control pressure line L2 through an inlet H3 and an outlet H4 and a spring chamber 41a having a function of a flow path is formed at a lower portion thereof.

That is, the valve housing 41 is connected to the accumulator 20 through the control line L2 and the outlet H4 is connected to the clutch 30 via the control line L2. And is connected to the hydraulic chamber 53 of the hydraulic pump.

The piston 43 is formed inside the valve housing 41 and reciprocates by the control pressure supplied through the control pressure line L2 to open and close the inlet H3, On / off operation of connecting or disconnecting the battery.

One end of the valve spring 45 is hinged to the center of the piston 43 and the other end of the valve spring 45 is hinged to one side of the lower portion of the spring chamber 41a, And provides operating force to the piston (43) toward the inlet (H3) while acting within a constant spring angle range.

Here, the piston valve 40 is operated by varying the on / off operation pressure of the piston valve 40 using the hysteresis effect according to the operating angle [theta] of the valve spring 45, The control pressure line L2 is shut off to cut off the control pressure to the hydraulic chamber 53 of the clutch 30 when the charging pressure becomes lower than the minimum target pressure P1 and the charging hydraulic pressure becomes higher than the maximum target pressure P2 , The control pressure line (L2) is connected to supply the control pressure to the hydraulic chamber (53) of the clutch (30).

That is, the valve 43 of the piston 43 connects the power of the engine to the oil pump 10 only when the oil pressure of the accumulator 20 is below the minimum target pressure P1, The power of the engine is shut off to stop the oil pump 10 to minimize the drive loss of the oil pump 10. [

Hereinafter, the operation according to the hysteresis effect of the piston valve 40 will be described in more detail with reference to FIGS. 3 and 4. FIG.

First, the constant of the valve spring 45 is' k ', the height of the valve spring 45 is'a', the initial length of the valve spring 45 is' I ₀ ', the force of the valve spring 45 is' F _P 'and the cross-sectional area of the piston 43 to' A ', the force (horizontal force) pushing the piston 43 by the valve spring 45 is F' The pressure (i.e., control pressure) is as follows.

The required operating pressure P for operating the piston 43 (i.e., the control pressure)

이다

to be

That is, the required operating pressure 'P' varies depending on the operating angle '?' Of the valve spring 45.

As described above, as the required operating pressure (i.e., the control pressure) 'P' required for the on / off operation of the piston valve 40 is different, the accumulator 20 always receives the minimum target pressure P1, And the oil pump 10 stops when the charged hydraulic pressure in the accumulator 20 reaches the maximum target pressure P2 by operating at the lower limit target pressure P1 or lower The valve spring 45 is designed so as not to operate until it is lower than the minimum target pressure P1 to minimize the drive loss of the oil pump 10. [

A check valve (not shown) is provided on the hydraulic line L1 that connects the discharge side of the oil pump 10 and the accumulator 20 to prevent the charge oil pressure in the accumulator 20 from flowing back to the oil pump 10 side. (70).

5 is a sectional view of an on state of a check valve applied to an oil supply apparatus according to an embodiment of the present invention.

5, a check ball 73 is supported by a ball spring 75 in a ball housing 71 provided on the hydraulic line L1 so that the back flow of the charging oil pressure To block the hydraulic line L1.

Hereinafter, the operation of the oil supply apparatus for an automatic transmission according to the embodiment of the present invention will be described.

2, when the oil pump 10 is stopped, a control pressure is supplied to the hydraulic chamber 53 so that the friction disc 31a on the clutch case 31 and the friction pad 31a on the rotary disc 33 The power of the output shaft 50 is not transmitted to the oil pump 10 in a state where the output shaft 33a is away.

At this time, the piston valve 40 is in the on state as shown in FIG. 3, and the operating force (i.e., F _P ) of the valve spring 45 is smaller than the control pressure P supplied from the accumulator 20 The piston 43 moves to the left in the figure and the control pressure P is supplied to the hydraulic chamber 53. [ At this time, the control pressure P may be the maximum target pressure P2.

5, the check valve 73 is closed by the ball spring 75 and the charged oil pressure in the accumulator 20 flows backward ≪ / RTI >

4, the piston valve 40 is in the off state and the valve spring 45 is in the off state, as shown in FIG. 4, when the charged hydraulic pressure in the accumulator 20 is lowered below the minimum target pressure P1. The control pressure P supplied to the hydraulic chamber 53 is blocked by the piston 43 moving to the right in the figure so that the operating force (i.e., F _P ) of the piston 43 becomes larger than the control pressure P supplied from the accumulator 20 . At this time, the control pressure P may be the minimum target pressure P1.

6, the clutch 30 is closed when the control pressure P supplied to the hydraulic pressure chamber 53 is cut off and the friction disc 31a on the clutch case 31 The friction pad 33a on the rotary disk 33 is frictionally engaged so that the power of the output shaft 50 is transmitted to the oil pump 10 and the oil pump 10 is driven.

Then, the hydraulic pressure generated by the oil pump 10 is charged to the accumulator 20 through the hydraulic line L1.

7, the check valve 70 compresses the ball spring 75 by the oil pressure supplied from the oil pump 10 to connect the oil lines, And supplies the oil pressure supplied from the oil pump 10 to the accumulator 20.

3, when the charged hydraulic pressure in the accumulator 20 is charged to the maximum target pressure P2 or higher in a state where the accumulator 20 is filled with the hydraulic pressure, The operating force (i.e., F _P ) of the valve spring 45 becomes smaller than the control pressure P supplied from the accumulator 20 so that the piston 43 moves to the left in the drawing, And the control pressure P is supplied to the control valve 53 as shown in Fig. At this time, the control pressure P becomes the maximum target pressure P2.

2, the clutch 30 is again supplied with the control pressure P to the hydraulic pressure chamber 53 so that the friction disc 31a on the clutch case 31 and the friction pad 31a on the rotating disc 33 The power of the output shaft 50 transmitted to the oil pump 10 is cut off and the oil pump 10 is stopped.

As a result, when the oil pump 10 is stopped, the accumulator 20 is not hydraulically charged, and the check valve 70 is turned on again, as shown in FIG. 5, Is blocked by the ball spring 75 to prevent the charged hydraulic pressure in the accumulator 20 from flowing backward.

Accordingly, the oil supply device for an automatic transmission according to the embodiment of the present invention can be used to connect or disconnect the power of the engine transmitted to the mechanical oil pump 10 by using the clutch 30 that operates in accordance with the charging hydraulic pressure of the accumulator 20 Thereby minimizing the loss of unnecessary oil pressure generated from the oil pump 10, thereby improving fuel economy.

It is also possible to control the operating point of the clutch 30 by varying the on-off operating pressure of the piston valve 40 using the operating pressure change using the hysteresis effect according to the operating angle of the valve spring 45, The driving loss due to the energy conversion of the oil pump 10 can be minimized by driving the oil pump 10 in an on demand system.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, Includes all changes to the scope permitted.

10: Oil pump
11: Case
13: inner gear
15: outer gear
20: Accumulator
30: Clutch
31: clutch case
31a: Friction disk
33: rotating disk
33a: friction pad
37: Spline shaft
35: clutch spring
40: Piston valve
41: valve housing
41a: spring chamber
43: Piston
45: Valve spring
50: Output shaft
51: spline portion
53: Hydraulic chamber
55: Oil hole
57: Adapter
60: Hydraulic consumption part
70: Check valve
71: Ball housing
73: Check ball
75: Ball spring
L1: Hydraulic line
L2: Control line

Claims (9)

1. An oil supply apparatus for an automatic transmission, comprising:
An internal gear connected to an output shaft of an engine for an external gear intermeshed in a case having an inlet port and a discharge port, the oil pump generating hydraulic pressure while rotating;
An accumulator connected to the discharge side of the oil pump through an oil line to charge the oil pressure generated by the oil pump;
A clutch configured to be interposed between an inner gear of the oil pump and an output shaft of the engine and to control the power of the engine to be transmitted to the inner gear using the oil pressure of the accumulator as a control pressure;
A piston valve configured on a control pressure line connecting the accumulator and the clutch and controlling the control pressure supplied to the clutch along the control pressure line while being turned on and off according to a charging hydraulic pressure of the accumulator;
And an oil supply device for an automatic transmission. The method according to claim 1,
Wherein the oil pump is an internal gear pump. 3. The method of claim 2,
And a check valve is provided on the hydraulic line so as to prevent the charged hydraulic pressure in the accumulator from flowing back to the oil pump. The method according to claim 1,
The clutch
A spline section and a hydraulic chamber are formed on the inner peripheral surface of the front end of the output shaft,
A clutch case formed in a cylindrical shape and fixed to a rotation center of the inner gear, and a friction disc formed on an inner upper surface;
A rotating disk disposed inside the clutch case corresponding to the friction disk and spline shaft formed at the center of the top surface passes through the clutch case and spline coupled to the spline portion of the output shaft to rotate integrally with the output shaft;
A clutch spring interposed between an inner bottom surface of the clutch case and the rotary disc to provide a pressing force to frictionally couple the rotary disc to the friction disc;
And an oil supply device for an automatic transmission. 5. The method of claim 4,
The hydraulic chamber
An oil for an automatic transmission which is formed as a space portion inside the spline portion on the inner circumferential surface of the front end portion of the output shaft so as to be supplied with the control oil pressure of the accumulator and connected to the control pressure line through an adapter provided corresponding to the oil hole on the output shaft, Supply device. 5. The method of claim 4,
The spline shaft
And a tip end is disposed corresponding to the hydraulic chamber so as to move in an axial direction in accordance with a pressure of the hydraulic chamber. 5. The method of claim 4,
On the rotating disk
And a friction pad is provided on an upper surface corresponding to the friction disk. The method according to claim 1,
The piston valve
A valve housing installed on the control pressure line through an inlet and an outlet and forming a spring seal at a lower portion thereof;
A piston reciprocating by a control pressure supplied through the control pressure line in the valve housing and being operated on and off while opening or closing the inlet;
And a valve spring that is hinged to one side of the lower portion of the spring chamber and hinged to the lower end of the spring chamber to move within a predetermined angle range of the spring while providing an operating force to the piston toward the inlet side, spring;
And an oil supply device for an automatic transmission. 9. The method of claim 8,
The valve housing
Wherein the inlet is connected to the accumulator via a control line, and the outlet is connected to the clutch through a control line.

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