Power plant

Abstract

To simplify a coupling part of a transaxle with a connection member.SOLUTION: A power plant 10 includes an engine 20, and a transaxle 30 connected to the engine 20. The power plant 10 includes a connection member 40 connecting the cylinder block 21 of the engine 20 and an upper portion 31 of the transaxle 30 located above a portion of the transaxle 30 connected with the engine 20. The connection member 40 includes a dashpot 41.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a power plant including an engine and a transaxle. [Background technology]

[0002] The vehicle drive device disclosed in Patent Document 1 includes an engine and a power transmission device connected to the engine. The vehicle drive device further includes a reinforcing member connected to both the engine and the power transmission device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2024-58909 Summary of the Invention [Problem to be solved by the invention]

[0004] Vibrations generated by the engine are transmitted to the power transmission device via the reinforcing member. That is, axial force resulting from vibrations generated by the engine is input to the connection points of the reinforcing member in the power transmission device. Therefore, in the above-described configuration, the strength of the connection points must be sufficiently high. [Means for solving the problem]

[0005] A power plant that solves the above problem includes an engine, a transaxle connected to the engine, and a connecting member that connects the cylinder block of the engine to an upper portion of the transaxle that is above the portion that is connected to the engine. The connecting member includes a dash pod. [Effects of the Invention]

[0006] The above power plant has the advantage of being able to simplify the fastening points with the connecting member in the transaxle. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram showing a power plant according to an embodiment. [Figure 2] FIG. 2 is a graph showing the relationship between the sound pressure of noise generated by the power plant and the engine speed. [Figure 3] FIG. 3 is a schematic diagram showing a power plant according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0008] An embodiment of the power plant will be described below with reference to FIG. 1 or 2. FIG. <Power plant configuration> As shown in FIG. 1, the power plant 10 includes an engine 20 and a transaxle 30 connected to the engine 20 .

[0009] The engine 20 includes a cylinder block 21 and a cylinder head 22 attached to the cylinder block 21. A plurality of cylinders 23 are formed in the engine 20 and arranged along a cylinder arrangement direction. Pistons reciprocate within the plurality of cylinders 23. Of the piston movement directions, the direction approaching the cylinder head 22 is referred to as the upward direction Z1. The opposite direction to the upward direction Z1 is referred to as the downward direction Z2. The downward direction Z2 can be said to be the movement direction of the piston moving away from the cylinder head 22.

[0010] The engine 20 includes a crankcase 24 attached to the cylinder block 21 and an oil pan 25 attached to the crankcase 24. The crankcase 24 is located on the opposite side of the cylinder block 21 from the cylinder head 22. The oil pan 25 is located on the opposite side of the crankcase 24 from the cylinder block 21.

[0011] The engine 20 includes a crankshaft 26, which is the output shaft of the engine 20. The crankshaft 26 rotates as pistons reciprocate within the multiple cylinders 23. The crankshaft 26 protrudes from the crankcase 24 toward the transaxle 30.

[0012] The output torque of the engine 20 is input to the transaxle 30 via a crankshaft 26. The transaxle 30 includes, for example, a transmission mechanism. A portion of the transaxle 30 that is above the connection portion with the engine 20 in the Z1 direction is referred to as an "upper portion 31 of the transaxle 30."

[0013] The power plant 10 includes a connecting member 40. The connecting member 40 connects the cylinder block 21 of the engine 20 and the upper portion 31 of the transaxle 30. A first end of the connecting member 40 is fastened to the cylinder block 21. A second end of the connecting member 40 is fastened to the upper portion 31. The connecting member 40 includes a dash pod 41. The dash pod 41 is disposed between the first end and the second end. The dash pod 41 is a damper that uses viscous friction to resist sudden movement. When the engine 20 is operating, resonance occurs due to the structure of the power plant 10. Vibrations are input from the engine 20 to the transaxle 30, displacing the upper portion 31 in a direction Y2 away from the cylinder block 21 and displacing the upper portion 31 in a direction Y1 toward the cylinder block 21. This type of resonance is also referred to as "bending resonance." Dash pod 41 has the function of suppressing vibration of transaxle 30 by damping vibration caused by such bending resonance.

[0014] <Operation of this embodiment> The operation when the engine 20 is operating will be described with reference to Fig. 2. Fig. 2 shows the relationship between the sound pressure of noise caused by bending resonance and the engine speed NE. Specifically, the solid line in Fig. 2 shows the relationship between the sound pressure of noise and the engine speed NE in this embodiment. The dashed line in Fig. 2 shows the relationship between the sound pressure of noise and the engine speed NE in a comparative example.

[0015] In the comparative example, a stay is used as the connecting member, which does not have the function of damping vibrations of the transaxle 30 caused by bending resonance. Therefore, when the engine speed NE is in the range from the first speed NE1 to the second speed NE2, the sound pressure of the noise becomes high, as shown by the dashed line in Figure 2.

[0016] In contrast, in this embodiment, the connecting member 40 includes a dash pod 41. Therefore, the dash pod 41 damps vibrations of the transaxle 30 caused by bending resonance. This damps vibrations of the transaxle 30. As a result, when the engine speed NE is a value in the range from the first speed NE1 to the second speed NE2, the sound pressure of noise is reduced compared to the comparative example, as shown by the solid line in FIG. 2. Therefore, by providing the connecting member 40 with the dash pod 41, the noise generated by the power plant 10 is reduced.

[0017] <Effects of this embodiment> (1) Vibrations caused by the bending resonance are input from the engine 20 to the fastening points of the connecting member 40 in the upper portion 31 of the transaxle 30 via the connecting member 40. The connecting member 40 can attenuate such vibrations. Therefore, the power plant 10 can simplify the strength of the fastening points while suppressing damage to the fastening points.

[0018] <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.

[0019] 3 shows a modified example of the power plant. A first plate member 51 is fastened to the cylinder block 21. A second plate member 52 is fastened to the upper portion 31 of the transaxle 30. A first end of the connecting member 40 is fastened to the first plate member 51. A second end of the connecting member 40 is fastened to the second plate member 52. With this modified power plant 10A, it is possible to obtain the same effects as with the power plant 10 of the above embodiment.

[0020] Furthermore, in the power plant 10A, the connecting member 40 does not need to be directly fastened to the cylinder block 21 and the transaxle 30. This increases the degree of freedom in the arrangement position of the connecting member 40. [Explanation of symbols]

[0021] 10, 10A...power plant, 20...engine, 21...cylinder block, 30...transaxle, 31...upper portion, 40...connecting member, 41...dash pod, 51...first plate member, 52...second plate member.

Claims

1. A power plant including an engine and a transaxle connected to the engine, a connecting member that connects a cylinder block of the engine and an upper portion of the transaxle that is above a connecting portion with the engine, The connecting member includes a dash pod Powerplant.

2. a first plate member fastened to the cylinder block; a second plate member fastened to the upper portion of the transaxle, A first end of the connecting member is fastened to the first plate member, and a second end of the connecting member is fastened to the second plate member. The power plant of claim 1 .

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