Torque tube fastening structure

Abstract

To securely fasten the torque tube to the mating component without any play, while also ensuring the ease of attachment and detachment of the torque tube in market services. [Solution] A torque tube 30 that holds a rotating shaft 31 inside is fastened to a mating member (engine 10, transaxle 20) via a knock pin 40, wherein the knock pin 31 is press-fitted into the mating member (engine 10, transaxle 20) and crimped and fixed to the torque tube 30 side when the rotating shaft 31 is in a positioning state.

Description

Technical Field

[0001] The present invention relates to a fastening structure of a torque tube.

Background Art

[0002] In a power train adopted in a vehicle or the like, as described in Patent Document 1, a torque tube that holds a rotating shaft such as a propeller shaft inside is fastened to a mating member such as an engine or a transaxle via a knock pin. A fastening structure of the torque tube is adopted.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a power train using a torque tube, during maintenance, it is difficult from the perspective of market services to attach and detach the entire power train from the vehicle. Therefore, it is required that the fastening surface of the torque tube can be separated from the fastening surface (mating surface) of the engine and the transaxle in the vehicle-mounted state.

[0005] Also, at the time of assembling the power train, the knock pin needs to be firmly fastened to both the torque tube and the mating member without play against excessive external inputs acting in the usage environment during vehicle travel, such as torque input on the engine side and road surface input on the transaxle.

[0006] However, generally, in the assembled state of the powertrain, there is manufacturing tolerance variation in the accuracy of the mounting position of the rotating shaft relative to the knock pin that secures it to the torque tube. If the variation is large, the rotating shaft held in the torque tube will experience a large misalignment of the axis at the connection point with the mating shaft held in the mating component (such as the engine's propeller shaft or the transaxle's input shaft). This makes it difficult to detach the rotating shaft and, consequently, the torque tube during market service, and as a result, it becomes impossible to attach or detach the torque tube to the engine and transaxle while it is installed in the vehicle.

[0007] The object of the present invention is to securely fasten the torque tube to the mating member without any play, while also ensuring the ease of attachment and detachment of the torque tube in market services. [Means for solving the problem]

[0008] The invention according to claim 1 is a torque tube fastening structure in which a torque tube that holds a rotating shaft inside is fastened to a mating member via a knock pin, wherein the knock pin is press-fitted into the mating member and crimped and fixed to the torque tube side when the rotating shaft is in a positioning state. [Effects of the Invention]

[0009] According to the present invention, the torque tube can be firmly fastened to the mating member without any play, while ensuring the ease of attachment and detachment of the torque tube in market services. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a schematic diagram showing one embodiment of the torque tube fastening structure according to the present invention. [Figure 2] Figure 2 is a schematic diagram illustrating the effects and benefits of the present invention. [Figure 3] Figure 3 is a schematic diagram showing a powertrain to which the present invention is applied. [Modes for carrying out the invention]

[0011] As one embodiment to which the present invention is applied, the powertrain 100 of a vehicle or the like is configured with a torque tube 30 interposed between the engine 10 and the transaxle 20, as shown in Figures 1 to 3.

[0012] The engine 10 and the transaxle 20 are mating components fastened to the torque tube 30. The torque tube 30 holds a rotating shaft (propeller shaft) 31 internally via a bearing 32. One end of the rotating shaft 31 is connected to the output shaft (not shown) of the engine 10, and the other end of the rotating shaft 31 is connected to the input shaft 21 to the transaxle 20. In Figure 2, the input shaft 21 of the transaxle 20 is held by the transaxle 20 via a bearing 22.

[0013] The torque tube 30 is fastened to the mating member, the transaxle 20, using knock pins 40 and knock holes 51 and 52 at the fastening surface. In the following description of this specification, only the fastening structure between the torque tube 30 and the transaxle 20 using knock pins 40 is illustrated and described (Figures 1 and 2), but a similar fastening structure using other knock pins and knock holes is also employed for the fastening between the torque tube 30 and the engine 10.

[0014] Furthermore, inside the torque tube 30 shown in Figures 1 and 2, the end of the rotating shaft 31 held by the torque tube 30 and the end of the input shaft 21 held by the transaxle 20 are connected by being inserted through a connecting sleeve 60 so as to be able to transmit rotational force.

[0015] Incidentally, in the assembled state of the powertrain 100, as shown in Figure 2, there is manufacturing tolerance variation in the assembly accuracy of the rotating shaft 31 relative to the knock pin 40 fixed to the torque tube 30 (the distance L between the knock pin 40 and the rotating shaft 31). That is, compared to the nominal tolerance state shown in Figure 2(A), the above assembly position accuracy varies greatly in the maximum tolerance state shown in Figure 2(B). In the case of Figure 2(B), the central axis of the rotating shaft 31 and the central axis of the connecting sleeve 60 to the input shaft 21 provided at the connection part become oblique, resulting in the rotating shaft 31 exerting a bending load on the connecting sleeve 60, making it difficult to detach the rotating shaft 31 and, consequently, the torque tube 30 during market service.

[0016] Therefore, in this embodiment, in order to securely fasten the torque tube 30 to the mating components, the engine 10 and transaxle 20, without any play, and to ensure the ease of attachment and detachment of the torque tube 30 in market service, the structure shown in Figure 1 was adopted. Specifically, the knock pin 40 is press-fitted into a knock hole 51 provided on the fastening surface of the transaxle 20 and fixed in the axial direction, and is crimped into a knock hole 52 provided on the fastening surface of the torque tube 30 when the rotating shaft 31 is in a positioning state.

[0017] Specifically, this is as follows: (1) and (2). (1) Depending on the manufacturing precision of the engine 10, transaxle 20, torque tube 30, etc., the knock hole 52 into which the knock pin 40 is inserted is made larger in diameter to the necessary extent in order to absorb enough play to allow for variations in the assembly position precision of the rotating shaft 31 relative to the knock pin 40 (distance L between the knock pin 40 and the rotating shaft 31).

[0018] (2) Press-fit the knock pin 40 fixed axially into the knock hole 51 on the side of the transaxle 20, and adjust the position of the knock hole 52 on the side of the torque tube 30 in the radial and axial directions within the range of the play described in (1) above. Thus, with the rotational shaft 31 held by the torque tube 30 in an assembled state where the assembly position accuracy with respect to the knock pin 40 can be ensured, the knock pin 40 is caulked and fixed to the knock hole 52 on the side of the torque tube 30.

[0019] In this embodiment, the cylindrical knock pin 40 is plastically deformed to expand its diameter while inserted into the knock hole 52 and is caulked to the inner diameter of the knock hole 52, resulting in a state where the aforementioned play is absorbed and a play-filled fixed state is achieved. In FIG. 1(B), 52A indicates the bush for forming the inner diameter of the knock hole 52, and 40A indicates the expanded diameter portion of the knock pin 40.

[0020] Therefore, the following operational effects are achieved according to this embodiment. (a) When assembling the power train 100, the knock pin 40 is press-fitted into the mating member (engine 10, transaxle 20) and caulked and fixed to the side of the torque tube 30 in a state where the rotational shaft 31 is positioned. Therefore, in an assembled state where the assembly position accuracy of the rotational shaft 31 with respect to the torque pin 40 fixed to the torque tube 30 is ensured to the required accuracy, the knock pin 40 is firmly fastened to both the torque tube 30 and the mating member without play, and vehicle performance can be ensured.

[0021] (b) During the assembly process of the power train 100, the knock pin 40 that has not yet been caulked to the side of the torque tube 30 is set with a certain amount of play with respect to the knock hole 52 on the side of the torque tube 30. Therefore, the knock hole 52 on the side of the torque tube 30 can be caulked to the knock pin 40 after the positions of the knock pin 40 and the knock hole 52 are adjusted in the radial and axial directions within the above-mentioned play range to ensure the assembly position accuracy of the rotational shaft 31 with respect to the knock pin 40.

[0022] That is, after absorbing the variation in the manufacturing tolerance of the assembly position accuracy of the rotation axis 31 with respect to the knock pin 40 fixed to the torque tube 30 within the range of the above-mentioned play, the torque tube 30 is caulked and fixed to the knock pin 40 to eliminate the play, and it is firmly fixed in the axial direction and the radial direction. As a result, the rotation axis 31 on the torque tube 30 side and the mating shaft on the side of the transfer axle 20 (or the engine 10) as the mating member can be connected in a positioning and assembling state where the axial misalignment between the two is eliminated. Thereby, the skew between the central axis of the rotation axis 31 and the central axis of the connection sleeve 60 of the input shaft 21 of the transfer axle 20 is not caused, facilitating the detachment of the rotation axis 31 and thus the disconnection of the torque tube 30 in the market service, and enabling the attachment and detachment of the torque tube 30 to the engine 10 and the transfer axle 20 in the vehicle-mounted state.

[0023] As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration of the present invention is not limited to this embodiment, and design changes and the like within the scope not departing from the gist of the present invention are also included in the present invention.

Industrial Applicability

[0024] In summary, according to the present invention, the torque tube can be firmly fastened to the mating member without play, and the attachability and detachability of the torque tube in the market service can be ensured.

Explanation of Reference Numerals

[0025] 10 Engine (mating member) 20 Transfer axle (mating member) 30 Torque tube 40 Knock pin

Claims

[Claim 1] A torque tube fastening structure in which a torque tube that holds a rotating shaft internally is fastened to a mating member via a knock pin, The knock pin is a fastening structure for a torque tube, which is press-fitted into the mating component and then crimped and fixed to the torque tube side while the rotating shaft is in a positioning state.

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