JP2018119566A - Lubrication circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lubrication circuit capable of securing a lubricant flow rate and suppressing heating or abrasion, even in a case where a first lubrication part is at predetermined low-speed rotation of a fluid pump.SOLUTION: The lubrication circuit (hydraulic circuit 1) includes a first lubrication circuit 3 configured to supply lubricant to a friction clutch 2 as a first lubrication part, a second lubrication circuit 5 configured to supply temperature-controlled lubricant to a differential gear 4 as a second lubrication part, through an oil warmer 7, and a hydraulic pump 6. The lubrication circuit also includes a check valve 10 configured to open in low-speed rotation of the hydraulic pump 6 to allow supply of lubricant from the second lubrication circuit 5 to the friction clutch 2, and inhibit supply of the lubricant from the second lubrication circuit 5 to the friction clutch 2 in high-speed rotation of the hydraulic pump 6.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a lubrication circuit including a first lubrication circuit and a second lubrication circuit that adjusts the temperature of a fluid.

  Conventionally, a lubrication circuit such as a hydraulic control circuit that controls an automatic transmission by hydraulic pressure supplied from a fluid pump (hydraulic pump) is known (see, for example, Patent Document 1). The hydraulic control circuit of Patent Document 1 not only controls the automatic transmission, but also plays a role of supplying a lubricating fluid to the components of the automatic transmission for lubrication and cooling.

JP-A-2006-156399

  The lubrication circuit has a first lubrication circuit that supplies lubricating oil as it is to the part (first lubrication part) that needs to be sufficiently cooled and lubricated, such as a friction clutch. In such a part (second lubrication part, for example, a differential gear, etc.), a second lubrication circuit that supplies lubricating oil whose temperature is adjusted to an appropriate temperature by a heat exchanger such as an oil warmer may be provided. Conceivable. However, when the fluid pump is at a low speed, which is less than a predetermined rotation, the amount of lubricating fluid supplied from the first lubrication circuit to the first lubrication part is small, and at a low speed when the first lubrication part is less than the predetermined rotation of the fluid pump. There is a risk of heat generation or wear.

  In view of the above, the present invention provides a lubrication circuit that can secure a lubricating flow rate and suppress heat generation or wear even when the first lubrication unit is at a low speed when the fluid pump is less than a predetermined speed. With the goal.

In order to achieve the above object, the present invention provides:
A first lubrication circuit (for example, the first lubrication of the embodiment) that supplies a lubricating fluid (for example, the lubricant of the embodiment; the same shall apply hereinafter) to the first lubrication part (for example, the friction clutch 2 of the embodiment; the same shall apply hereinafter). Circuit 3, the same shall apply hereinafter),
The second lubricating part (for example, the differential gear 4 of the embodiment; the same applies hereinafter) is supplied with the lubricating fluid whose temperature has been adjusted through a heat exchanger (for example, the oil warmer 7 of the embodiment; the same applies hereinafter). 2 lubrication circuits (for example, the second lubrication circuit 5 of the embodiment; the same applies hereinafter);
A lubrication circuit (e.g., hydraulic circuit 1 of the embodiment; the same applies hereinafter) including a fluid pump (e.g., the hydraulic pump 6 of the embodiment; the same applies hereinafter),
The fluid pump is opened at a low rotation time that is less than a predetermined rotation, allows the supply of the lubricating fluid from the second lubrication circuit to the first lubrication unit, and the fluid pump at a high rotation time that is equal to or higher than the predetermined rotation. A valve portion (for example, the check valve 10 of the embodiment; the same applies hereinafter) that prevents the supply of the lubricating fluid from the second lubrication circuit to the first lubrication portion is provided.

  Here, when the fluid pump is rotating less than a predetermined rotation, the temperature of the lubricating fluid is low and the viscosity is high, so the flow rate of the lubricating fluid flowing through the first lubricating circuit is small. On the other hand, since the lubricating fluid supplied from the second lubricating circuit to the second lubricating portion is heated by the heat exchanger of the second lubricating circuit, the temperature becomes high and the viscosity becomes low. Can be secured. In the present invention, the lubrication fluid is supplied from the second lubrication circuit to the first lubrication unit by the valve unit when the fluid pump is rotating at a low speed less than the predetermined rotation. Therefore, a sufficient lubricating fluid can be supplied to the first lubricating portion even at the time of low rotation.

  In the present invention, the valve portion is a check that is interposed in a communication path (for example, the communication path 9 of the embodiment; the same applies hereinafter) that connects the first lubrication circuit and the second lubrication circuit. The lubricating fluid that flows through the first lubricating circuit is the second lubricating circuit at the time of the low rotation when the fluid pump is less than the predetermined rotation. Preferably, the pressure is lower than that of the lubricating fluid flowing through the fluid, and the fluid pump is equal to or higher than the pressure of the lubricating fluid flowing through the second lubricating circuit during the high rotation, which is equal to or higher than the predetermined rotation.

  According to such a configuration, the valve portion does not need to be configured by a solenoid valve or the like, but is configured by a check valve, and the pressure of the lubricating fluid is higher in the second lubricating circuit than in the first lubricating circuit at a predetermined low speed. The check valve is automatically switched between the open and closed states by utilizing the fact that the pressure of the lubricating fluid flowing through the second lubricating circuit is less than the pressure of the lubricating fluid flowing through the first lubricating circuit at high revolutions. Therefore, the configuration can be simplified.

Explanatory drawing which shows typically embodiment of the lubrication circuit of this invention. Explanatory drawing which shows the lubrication circuit of this embodiment. Explanatory drawing which shows the cross section of the lubrication circuit of this embodiment. Explanatory drawing which shows a part of lubrication circuit of this embodiment.

  A hydraulic circuit according to an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, a hydraulic circuit 1 according to an embodiment of the present invention supplies lubricating oil to a power transmission device mounted on a vehicle (automobile), and a main shaft is connected to a friction clutch 2 provided in the power transmission device. The first lubrication circuit 3 for supplying the lubricating oil via the above, the second lubrication circuit 5 for supplying the temperature-adjusted lubricating oil to the differential gear 4 included in the power transmission device, and the drive source ENG (internal combustion engine, electric motor) And a hydraulic pump 6 that operates using the power of.

  The second lubricating circuit 5 includes an oil warmer 7 for exchanging heat between the engine coolant and the lubricating oil, and the choke 8. The lubricating oil adjusted to an appropriate temperature by the oil warmer 7 is passed through the choke 8. Supply to differential gear 4.

  The hydraulic circuit 1 is provided with a communication passage 9 that allows the first lubrication circuit 3 and the second lubrication circuit 5 to communicate with each other. FIG. 2 shows a portion where the communication path 9 and the first lubricating circuit 3 are connected. A check valve that allows the flow of lubricating oil from the second lubricating circuit 5 to the first lubricating circuit 3 and prevents the flowing of lubricating oil from the first lubricating circuit 3 to the second lubricating circuit 5 is provided in the communication path 9. 10 is interposed. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2 and shows the check valve 10. FIG. 4 shows a perspective view of a part where the check valve 10 is provided.

  As shown in FIG. 1, when the hydraulic pump 6 is operated, the lubricating oil accumulated in the oil pan 11 is sucked up through the strainer 12 and is supplied from the hydraulic pump 6 to the regulator valve 13. A part of the lubricating oil supplied to the regulator valve 13 is supplied to the friction clutch 2 and used as a lubricating oil for lubricating and cooling the friction clutch 2. A part of the lubricating oil supplied to the regulator valve 13 is guided to the oil warmer 7 via the torque converter TC.

  Here, the hydraulic pump 6 that operates using the drive source ENG of the vehicle has a low rotation of less than a predetermined rotation when the drive source ENG is a low speed rotation lower than the predetermined rotation. When the hydraulic pump 6 rotates at a low speed less than a predetermined rotation, the discharge amount of the hydraulic pump 6 is small, and the flow rate of the lubricating oil to the first lubricating circuit 3 is limited by the regulator valve 13 so as to keep the line pressure at a predetermined hydraulic pressure. In comparison with the first lubricating circuit 3, the lubricating oil is preferentially supplied from the regulator valve 13 in the second lubricating circuit 5. In addition, at low speed, the temperature of the lubricating oil tends to be low and the viscosity of the lubricating oil tends to be high. For this reason, the flow rate of the lubricating oil flowing through the first lubricating circuit 3 is reduced.

  Since the differential gear 4 generates less heat than the friction clutch 2, it is desirable to warm the lubricating oil supplied to the differential gear 4 to some extent in order to properly lubricate the differential gear 4 with the lubricating oil. Therefore, the lubricating oil flowing through the second lubricating circuit 5 is heated to an appropriate temperature by exchanging heat with the engine cooling water by the oil warmer 7 even at the time of low rotation.

  Therefore, at the time of low rotation, the flow rate of the lubricating oil in the second lubricating circuit 5 is larger than the flow rate in the first lubricating circuit 3, and the pressure of the lubricating oil in the second lubricating circuit 5 is increased. The check valve 10 is opened and the lubricating oil in the second lubricating circuit 5 is supplied to the friction clutch 2 through the communication passage 9 via the main shaft and the like, and a sufficient amount of lubricating oil is supplied to the friction clutch 2. And the friction clutch 2 can be properly lubricated. At this time, since the lubricating oil supplied to the friction clutch 2 is warmed by the oil warmer 7, it is at a relatively high temperature. However, since the drive source ENG is at a low speed, the amount of heat generated by the friction clutch 2 is also relatively high. It is low and the amount of lubricating oil supplied is large, so that a sufficient cooling effect can be obtained at low revolutions. In addition, although it is preferable that the effect of both lubrication and cooling is acquired, the power transmission device of this invention may exhibit only one effect of lubrication and cooling.

  When the drive source ENG exceeds a predetermined rotation speed and the hydraulic pump 6 rotates at a predetermined rotation or higher, the hydraulic pressure of the first lubrication circuit 3 becomes equal to or higher than the hydraulic pressure of the second lubrication circuit 5. For this reason, the check valve 10 is closed, and the check valve 10 prevents the lubricating oil of the second lubricating circuit 5 from being supplied to the first lubricating circuit 3.

  When the drive source ENG rotates at a high speed, the hydraulic pump 6 also rotates at a high speed. When the hydraulic pump 6 rotates at a high speed (when the hydraulic pump 6 rotates more than a predetermined speed), the heat generation amount of the friction clutch 2 may be increased, but the flow rate of the lubricating oil in the first lubricating circuit 3 is sufficient and the first lubrication is performed. The friction clutch 2 can be sufficiently lubricated and cooled with the lubricating oil of the circuit 3.

  Further, according to the hydraulic circuit 1 of the present embodiment, the check valve 10 automatically turns the hydraulic pump 6 at a low speed by utilizing the switching between the hydraulic pressure at the low speed of the hydraulic pump 6 and the hydraulic pressure at the high speed. Sometimes, the lubricating oil of the second lubricating circuit 5 is supplied to the friction clutch 2, and the lubricating oil of the second lubricating circuit 5 is prevented from being supplied to the friction clutch 2 at a high speed. Therefore, the configuration of the hydraulic circuit 1 can be simplified as compared with the case where the control is performed by a solenoid valve or the like.

  Note that the valve portion is not limited to a check valve, and may be, for example, an electromagnetic valve. “The flow rate of the fluid in the first lubrication circuit during low rotation when the fluid pump is less than a predetermined rotation is determined by the lubrication fluid in the second lubrication circuit. The effect of the present invention can be obtained.

  Note that “low rotation less than a predetermined rotation of the fluid pump” means that the rotation speed when the fluid pressure of the first lubrication circuit 3 is the same as the fluid pressure of the second lubrication circuit 5 is a predetermined rotation and less than this predetermined rotation. The high rotation is defined as the rotation speed when the fluid pressure of the first lubrication circuit 3 is the same as the fluid pressure of the second lubrication circuit 5, and the rotation of the region more than the predetermined rotation It is defined as

  In addition, the low rotation and the high rotation have a predetermined rotation as a threshold value, but the predetermined rotation can be regarded as an estimation of the fluid temperature based on the rotation speed, and the temperature of the fluid is detected and based on the fluid temperature. You may switch opening and closing of a valve part (check valve). In this case, the predetermined rotation may be changed according to the fluid temperature, or the boundary between the low rotation speed and the high rotation speed of the fluid pump can be set with the predetermined fluid temperature as a threshold value.

  In the present embodiment, the friction clutch 2 is used as the first lubrication part and the differential gear 4 is used as the second lubrication part. However, the first lubrication part and the second lubrication part of the present invention are not limited thereto.

DESCRIPTION OF SYMBOLS 1 Hydraulic circuit 2 Friction clutch 3 1st lubrication circuit 4 Differential gear 5 2nd lubrication circuit 6 Hydraulic pump 7 Oil warmer 8 Choke 9 Communication path 10 Check valve 11 Oil pan 12 Strainer 13 Regulator valve

Claims (2)

A first lubricating circuit for supplying a lubricating fluid to the first lubricating part;
A second lubrication circuit for supplying the lubrication fluid whose temperature is adjusted to the second lubrication part via a heat exchanger;
A lubricating circuit comprising a fluid pump for feeding the lubricating fluid,
The fluid pump is opened at a low rotation that is less than a predetermined rotation and allowed to supply the lubricating fluid from the second lubrication circuit to the first lubrication unit, and the fluid pump is operated at a high rotation that is equal to or higher than the predetermined rotation. A lubrication circuit, comprising: a valve unit that prevents supply of the lubricating fluid from the second lubrication circuit to the first lubrication unit. The lubrication circuit according to claim 1,
The valve portion is a check valve interposed in a communication path that connects the first lubrication circuit and the second lubrication circuit,
The lubricating fluid flowing through the first lubricating circuit has a lower pressure than the lubricating fluid flowing through the second lubricating circuit during the low rotation when the fluid pump is less than the predetermined rotation, and the fluid pump exceeds the predetermined rotation. A lubrication circuit, wherein the lubrication fluid has a pressure equal to or higher than the pressure of the lubricating fluid flowing through the second lubrication circuit during the high rotation.