Vehicle drive system

Abstract

To provide a vehicle driving device capable of suppressing deterioration of an adhesion degree between a prescribed contour component and a seal part caused by a difference between a thermal expansion amount of an internal combustion engine and a thermal expansion amount of a power transmission device.SOLUTION: A vehicle driving device 10 includes: an internal combustion engine 30; a power transmission device 20; and a reinforcement member 50 coupled to both of the internal combustion engine 30 and the power transmission device 20. A seal part 40 is interposed between a cylinder head 38 and a cam housing 39 that are located adjacent to each other in a direction along an axial line 31a of a cylinder 31. The reinforcement member 50 is coupled to the cam housing 39. In the cam housing 39, a first fastening portion 391 to which the reinforcement member 50 is fastened is provided at a position that does not overlap a contact portion 395 with which the seal part 40 is in contact in the com housing 39 in the direction along the axial line 31a.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vehicle drive system including an internal combustion engine and a power transmission device connected to the internal combustion engine. [Background technology]

[0002] Patent Document 1 discloses a vehicle drive device including an internal combustion engine, a transmission, and a stiffener. The stiffener is a reinforcing member for reinforcing the connection between the cylinder block of the internal combustion engine and the case of the transmission. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 9-195786 Summary of the Invention [Problem to be solved by the invention]

[0004] An internal combustion engine has a plurality of exterior components that form the exterior of the engine, arranged along the axis of the cylinders. The exterior components include, for example, a cylinder block, a cylinder head, and a cam housing. Sealing portions are interposed between adjacent exterior components along the axis to prevent oil and gas leakage.

[0005] When the vehicle drive system is operating, the internal combustion engine and the transmission case thermally expand. The amount of thermal expansion of the internal combustion engine in the direction along the axis differs from the amount of thermal expansion of the transmission case in the direction along the axis. Therefore, a load corresponding to the difference between the amount of thermal expansion of the internal combustion engine and the amount of thermal expansion of the transmission case is applied to the fastening portion of the stiffener in the internal combustion engine. If this load is transmitted to the contact portion between the seal portion of the external component to which the stiffener is fastened, there is a risk of a decrease in the degree of adhesion between the seal portion and the external component. [Means for solving the problem]

[0006] A vehicle drive device for solving the above problem includes an internal combustion engine having a plurality of cylinders, a power transmission device connected to the internal combustion engine, and a reinforcing member connected to both the internal combustion engine and the power transmission device. The internal combustion engine is configured such that a plurality of exterior components are arranged in a direction along the axis of the cylinders, and a seal portion is interposed between each of the exterior components adjacent to each other in the direction along the axis. Of the plurality of exterior components, the exterior component to which the reinforcing member is fastened is defined as a specified exterior component. In this case, a fastening portion of the specified exterior component to which the reinforcing member is fastened is located in a position, in the direction along the axis, that does not overlap with a contact portion of the specified exterior component with which the seal portion is in contact.

[0007] According to the vehicle drive system, the fastening portion is spaced apart from the contact portion along the cylinder axis. Therefore, even if a load that displaces the fastening portion along the axis due to a difference in thermal expansion between the internal combustion engine and the power transmission device is transmitted to the fastening portion via the reinforcing member, the load is unlikely to be transmitted to the contact portion. This makes it possible to prevent a decrease in the degree of adhesion between the specified outer shape component and the seal portion due to a difference in the thermal expansion between the internal combustion engine and the power transmission device along the axis. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a side view that schematically shows a part of a vehicle drive device according to an embodiment. [Figure 2] FIG. 2 is a plan view schematically showing a part of the vehicle drive device of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of a vehicle drive device will be described below with reference to FIGS. 1, the vehicle drive system 10 includes an internal combustion engine 30 and a power transmission system 20. Hereinafter, the vehicle drive system 10 will be simply referred to as the "drive system 10."

[0010] <Configuration of the power transmission device> The power transmission device 20 is connected to the internal combustion engine 30. The power transmission device 20 includes a transmission device 21 and a power control device 22. The transmission device 21 has a speed change device and at least one electric motor. The power control device 22 is a device that adjusts the power supplied to the electric motor. The power control device 22 has a device case and a power supply circuit housed in the device case. The transmission device 21 is connected to the internal combustion engine 30. The power control device 22 is arranged on the transmission device 21.

[0011] <Configuration of an internal combustion engine> 1 and 2, the internal combustion engine 30 includes a plurality of cylinders 31. The internal combustion engine 30 is an in-line internal combustion engine. Of the directions in which the plurality of cylinders 31 are arranged, the direction away from the power transmission device 20 is referred to as the "cylinder arrangement direction X1." Each of the plurality of cylinders 31 houses a piston 32 that reciprocates in a direction along an axis 31a of the cylinder 31.

[0012] The internal combustion engine 30 includes a plurality of exterior components that form the exterior of the internal combustion engine 30. The plurality of exterior components include an oil pan 35, a crankcase 36, a cylinder block 37, a cylinder head 38, and a cam housing 39. The oil pan 35, the crankcase 36, the cylinder block 37, the cylinder head 38, and the cam housing 39 are aligned in a direction along the axis 31a of the cylinder 31. Specifically, the crankcase 36 is attached to the lower part of the cylinder block 37. The oil pan 35 is attached to the lower part of the crankcase 36. The cylinder head 38 is attached to the upper part of the cylinder block 37. The cam housing 39 is attached to the upper part of the cylinder head 38. Among the directions along the axis 31a, the direction in which the oil pan 35, crankcase 36, cylinder block 37, cylinder head 38, and cam housing 39 are arranged in this order is called the "first axial direction Y1," and the direction opposite to the first axial direction Y1 is called the "second axial direction Y2."

[0013] A seal portion that suppresses oil and gas leakage is interposed between each of the exterior components that are adjacent to each other in the first axial direction Y1. For example, the seal portion 40 is an FIPG. FIPG is an abbreviation for "Formed In Place Gasket." The seal portion disposed between the cylinder head 38 and the cam housing 39 is called the "seal portion 40."

[0014] An imaginary line perpendicular to both the first axial direction Y1 and the cylinder arrangement direction X1 is referred to as a horizontal line Z (see FIG. 2). One of the directions along the horizontal line Z is referred to as a first horizontal direction Z1, and the other is referred to as a second horizontal direction Z2. In this embodiment, the first horizontal direction Z1 corresponds to the "specified direction."

[0015] <Structure for reinforcing the connection between an internal combustion engine and a power transmission device> The drive device 10 includes a reinforcing member 50 that is connected to both the internal combustion engine 30 and the power transmission device 20. The reinforcing member 50 includes a connecting member 51, a first connecting member 53, and a second connecting member 55.

[0016] The connecting member 51 is fastened to a specified exterior component, which is one of multiple exterior components of the internal combustion engine 30. In this embodiment, the specified exterior component is the cam housing 39. The connecting member 51 is fastened to the cam housing 39 at both a central portion of the cam housing 39 in the direction along the horizontal straight line Z and a portion of the cam housing 39 further in the first horizontal direction Z1 than the central portion. The portion of the cam housing 39 at the central portion where the connecting member 51 is fastened is referred to as a "first fastening portion 391." The portion of the cam housing 39 at the portion of the cam housing 39 further in the first horizontal direction Z1 than the central portion where the connecting member 51 is fastened is referred to as a "second fastening portion 392."

[0017] The first fastening portion 391 is a cylindrical boss that protrudes toward the power control device 22. In this embodiment, a bolt 61 fastens the first fastening portion 391 of the cam housing 39 to the connecting member 51. That is, a shaft portion 61a of the bolt 61 is screwed into the first fastening portion 391.

[0018] The second fastening portion 392 is a cylindrical boss that protrudes toward the power control device 22. In this embodiment, the bolt 62 fastens the second fastening portion 392 of the cam housing 39 to the connecting member 51. That is, the shank of the bolt 62 is screwed into the second fastening portion 392.

[0019] 1, the first fastening portion 391 and the second fastening portion 392 are arranged so as not to overlap a contact portion 395 with the seal portion 40 of the cam housing 39 in the direction along the axis 31a of the cylinder 31. Specifically, the first fastening portion 391 and the second connecting member 55 are arranged further in the first axial direction Y1 than the contact portion 395.

[0020] Furthermore, in cam housing 39, a weak portion having lower rigidity in the direction along axis 31a than other portions is provided between first fastening portion 391 and contact portion 395 in the direction along axis 31a of cylinder 31. Specifically, in cam housing 39, a recess 397 is provided between first fastening portion 391 and contact portion 395 in the direction along axis 31a. Recess 397 constitutes the weak portion. Recess 397 is formed so as to open to opposing surface 39a of a portion of the surface of cam housing 39 that faces power control device 22.

[0021] In this embodiment, an internal space 39S is formed near first fastening portion 391 inside cam housing 39. Therefore, by providing recess 397 in cam housing 39, a thin-walled portion 398 that is thinner than the other portions of cam housing 39 is formed between recess 397 and internal space 39S. This thin-walled portion 398 is more easily deformed than the other portions. Therefore, thin-walled portion 398 can be made to function as a fragile portion.

[0022] A first end 531 of the first coupling member 53 is fastened to the connecting member 51. A second end 532 of the first coupling member 53 is coupled to the case of the power control device 22 of the power transmission device 20. In other words, the first coupling member 53 is fastened to the power transmission device 20 at a position farther away from the first fastening portion 391 in the second axial direction Y2.

[0023] A first end 531 of the first joining member 53 is fastened to the connecting member 51 by a bolt 63. The fastening portion between the first joining member 53 and the connecting member 51 is disposed at substantially the same position as the first fastening portion 391 in the direction along the horizontal straight line Z.

[0024] The second end 532 of the first coupling member 53 is fastened by a bolt to the case of the power control device 22. More specifically, the second end 532 of the first coupling member 53 is fastened to the center of the case of the power control device 22 in the direction along the horizontal straight line Z.

[0025] The second connecting member 55 is disposed further in the first lateral direction Z1 than the first connecting member 53. A first end 551 of the second connecting member 55 is fastened to the connecting member 51. A second end 552 of the second connecting member 55 is coupled to the case of the power control device 22 of the power transmission device 20.

[0026] The fastening portion between the second connecting member 55 and the connecting member 51 is located further in the first horizontal direction Z1 than the fastening portion between the first connecting member 53 and the connecting member 51. The fastening portion between the second connecting member 55 and the power control device 22 is located further in the first horizontal direction Z1 than the fastening portion between the first connecting member 53 and the power control device 22.

[0027] <Action and effect> The reinforcing member 50 connects the power control device 22 and the cam housing 39. This suppresses vibration of the power control device 22. Furthermore, vibration of the internal combustion engine 30 is suppressed.

[0028] When the internal combustion engine 30 is operating, fuel is burned in the multiple cylinders 31 of the internal combustion engine 30, causing thermal expansion of the internal combustion engine 30. At this time, the amount of thermal expansion of the internal combustion engine 30 in the direction along the axis 31a is greater than the amount of thermal expansion of the power transmission device 20 in the direction along the axis 31a. Therefore, a load caused by the difference between the amount of thermal expansion of the internal combustion engine 30 and the amount of thermal expansion of the power transmission device 20 is input from the reinforcing member 50 to the first fastening portion 391 of the cam housing 39 of the internal combustion engine 30.

[0029] In this embodiment, the first fastening portion 391 is spaced apart from a contact portion 395 with the seal portion 40 in the direction along the axis 31a of the cylinder 31. Therefore, even if a load that displaces the first fastening portion 391 in the direction along the axis 31a is transmitted to the first fastening portion 391 via the reinforcing member 50, the load is unlikely to be transmitted to the contact portion 395. This is because the load is attenuated between the first fastening portion 391 and the contact portion 395. As a result, the drive device 10 can suppress a decrease in the degree of adhesion between the cam housing 39 and the seal portion 40 that is caused by a difference between the amount of thermal expansion of the internal combustion engine 30 and the amount of thermal expansion of the power transmission device 20.

[0030] Furthermore, a thin-walled portion 398, which is a weak portion having lower rigidity in the direction along the axis 31a than other portions, is formed in the cam housing 39 between the first fastening portion 391 and the contact portion 395. The thin-walled portion 398 can be formed by providing a recess 397 in the cam housing 39. By providing the recess 397 in the cam housing 39 in this manner, when the load is transmitted to the first fastening portion 391, the first fastening portion 391 and the periphery thereof are more likely to deform. For example, the thin-walled portion 398 is deformed. The input of the load causes the first fastening portion 391 and the periphery thereof to deform, making it more difficult for the load to be transmitted to the contact portion 395. This further enhances the effect of suppressing the transmission of the load to the contact portion 395.

[0031] The reinforcing member 50 has a first connecting member 53 and a second connecting member 55. The first connecting member 53 and the second connecting member 55 are disposed apart in the direction along the horizontal straight line Z. That is, the second fastening portion 392 is spaced apart from the first fastening portion 391 in the first horizontal direction Z1. This makes it possible to suppress deformation such as twisting of the power transmission device 20 relative to the internal combustion engine 30.

[0032] <Example of change> The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other within the scope of technical compatibility.

[0033] If the power transmission device 20 and the internal combustion engine 30 are connected using the first connecting member 53, the second connecting member 55 may be omitted. In this case, the connecting member 51 may be omitted, and the first fastening portion 391 may be directly connected to a component of the internal combustion engine 30.

[0034] If the first fastening portion 391 and the contact portion 395 can be positioned sufficiently apart, the cam housing 39 does not need to have a weakened portion. The sealing portion may be a liquid gasket other than FIPG. Examples of liquid gaskets other than FIPG include CIPG. CIPG is an abbreviation for "Cured In Place Gasket."

[0035] In the above embodiment, the reinforcing member is fastened to the cam housing 39, but the external component to which the reinforcing member is fastened may be a member other than the cam housing 39. For example, the reinforcing member may be fastened to the cylinder head 38.

[0036] The expression "at least one" used herein means "one or more" of the desired options. As an example, the expression "at least one" used herein means "only one option" or "both of two options" if the number of options is two. As another example, the expression "at least one" used herein means "only one option" or "any combination of two or more options" if the number of options is three or more. [Explanation of symbols]

[0037] 10...drive unit (vehicle drive unit), 20...power transmission unit, 30...internal combustion engine, 31...cylinder, 31a...axis, 35...oil pan, 36...crankcase, 37...cylinder block, 38...cylinder head, 39...cam housing, 391...first fastening portion, 392...second fastening portion, 395...contact portion, 397...recess, 40...sealing portion, 50...reinforcing member, 51...connecting member, 53...first connecting member, 55...second connecting member.

Claims

1. an internal combustion engine having a plurality of cylinders; a power transmission device connected to the internal combustion engine; and a reinforcing member connected to both the internal combustion engine and the power transmission device, The internal combustion engine is configured such that a plurality of exterior components are arranged in a direction along the axis of the cylinder, and a seal portion is interposed between each of the exterior components adjacent to each other in the direction along the axis, When the exterior component to which the reinforcing member is fastened is defined as a specified exterior component among the plurality of exterior components, a fastening portion to which the reinforcing member is fastened in the specified external component is provided at a position that does not overlap, in a direction along the axis, a contact portion to which the seal portion is in contact in the specified external component, the reinforcing member has a first connecting member and a second connecting member connected to the power transmission device, and a connecting member connected to the specified external component, When a direction perpendicular to both the direction along the axis and the direction of cylinder arrangement of the internal combustion engine is defined as a specified direction, and the fastening portion of the specified outer component is defined as a first fastening portion, the first coupling member is coupled to the connecting member, the second coupling member is fastened to the power transmission device at a position spaced apart in the specified direction from a fastening portion of the power transmission device where the second coupling member is fastened to the first coupling member, and the fastening portion of the connecting member is fastened to the connecting member at a position spaced apart in the specified direction from a fastening portion of the connecting member where the first coupling member is fastened to the connecting member, The connecting member is fastened to the specified external component at a position spaced apart from the first fastening portion in the specified direction. Vehicle drive system.

2. In the specified external component, a weak portion having a lower rigidity in the direction along the axis than other portions is provided between the fastening portion and the contact portion in the direction along the axis. The vehicle drive system according to claim 1 .

3. In the specified external component, a recess is formed between the fastening portion and the contact portion in the direction along the axis. The vehicle drive system according to claim 1 .

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