transfer

Abstract

To provide a transfer device that can suppress the increase in the size of the transfer device. [Solution] A transfer case 22 comprising a case 40 and a chain 54 which is a power transmission member housed inside the case 40, (a) The case 40 is formed by fastening together a first case member 42 and a second case member 44, which are multiple case members, at a mating surface 46; (b) A protector 60, which is a protective member that suppresses damage to the case 40, is provided between the inner wall surface 40i of the case 40 and the chain 54; and (c) The protector 60 is fastened to the mating surface 46 with bolts 70.

Description

Technical Field

[0001] The present invention relates to a transfer that includes a case and a chain as a power transmission member housed in the case.

Background Art

[0002] A transfer including a case and a chain as a power transmission member housed in the case is known. For example, the transfer described in Patent Document 1 is such a transfer.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when a chain is provided in a case, there is a risk that the case may be damaged due to the chain colliding with the case. Therefore, in order to prevent damage to the case, it is necessary to set a clearance with respect to the distance between the inner wall surface of the case and the chain so that the chain does not collide with the case. As a result, the size of the transfer becomes large.

[0005] The present invention has been made against the background of the above circumstances, and an object thereof is to provide a transfer that can suppress an increase in the size of the transfer.

Means for Solving the Problems

[0006] The gist of the present invention is a transfer comprising a case and a chain which is a power transmission member housed in the case, wherein (a) the case is made up of a plurality of case members fastened together at mating surfaces, (b) a protective member is provided between the inner wall surface of the case and the chain to suppress damage to the case, and (c) the protective member is fastened to the mating surfaces with bolts. [Effects of the Invention]

[0007] According to the transfer of the present invention, (a) the case is formed by fastening a plurality of case members at mating surfaces, (b) a protective member is provided between the inner wall surface of the case and the chain to suppress damage to the case, and (c) the protective member is fastened to the mating surface with bolts. In this way, when a protective member is provided between the inner wall surface of the case and the chain to suppress damage to the case, the distance between the inner wall surface of the case and the chain can be shortened compared to when no protective member is provided. This suppresses an increase in the size of the transfer. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram of a vehicle equipped with a transfer case according to an embodiment of the present invention. [Figure 2] This is a perspective view of an example of a protector. [Figure 3] This diagram illustrates the attachment of the protector to the case, and is a schematic view of the cross-section along the cutting line III-III shown in Figure 1, as seen in the direction of the arrow. [Modes for carrying out the invention]

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that in the embodiments, the drawings have been simplified or modified as appropriate, and the dimensional ratios and shapes of each part are not necessarily depicted accurately. [Examples]

[0010] Figure 1 is a schematic diagram of a vehicle 10 equipped with a transfer case 22 according to an embodiment of the present invention.

[0011] Vehicle 10 is equipped with an engine 12 as a power source for driving, a pair of front wheels 14 (hereinafter simply referred to as "front wheels 14"), a pair of rear wheels 16 (hereinafter simply referred to as "rear wheels 16"), and a power transmission device 18 that transmits power from the engine 12 to the front wheels 14 and rear wheels 16, respectively. The rear wheels 16 are the main drive wheels, which are driven wheels in both two-wheel drive and four-wheel drive modes. The front wheels 14 are the secondary drive wheels, which are driven wheels in two-wheel drive mode and drive wheels in four-wheel drive mode. Vehicle 10 is a four-wheel drive vehicle based on a Front Engine Rear Drive (FR) system. The engine 12 is a well-known internal combustion engine.

[0012] The power transmission device 18 includes a transmission 20 in the power transmission path between the engine 12 and the transfer case 22, and the transmission 20 has a well-known configuration. The transfer case 22 is a front and rear wheel power distribution device that distributes all of the engine 12's power to the rear wheels 16, or distributes the engine 12's power to the front wheels 14 and the rear wheels 16, respectively. The power transmission device 18 includes, in order from the transfer case 22 side, a front propeller shaft 24, a front wheel differential gear 28, and a pair of front wheel axles 32 in the power transmission path between the transfer case 22 and the front wheels 14, and these have a well-known configuration. The power transmission device 18 also includes, in order from the transfer case 22 side, a rear propeller shaft 26, a rear wheel differential gear 30, and a pair of rear wheel axles 34 in the power transmission path between the transfer case 22 and the rear wheels 16, and these have a well-known configuration.

[0013] The transfer case 22 includes a clutch (not shown) that can disconnect and reconnect power transmission between the transfer case 22 and the front propeller shaft 24. When this clutch is disengaged, the vehicle 10 can operate in two-wheel drive mode. When the clutch is engaged, the vehicle 10 can operate in four-wheel drive mode. The transfer case 22 comprises a case 40 and a chain 54, which is a power transmission member, housed within the case 40.

[0014] The chain 54 is wrapped around a sprocket 50 located on the engine 12 side with a first axis C1 as its center of rotation, and a sprocket 52 located on the front wheel 14 side with a second axis C2 as its center of rotation, in the power transmission path between the engine 12 and the front wheel 14. The first axis C1 and the second axis C2 are parallel. These sprockets 50 and 52, and the chain 54 constitute a well-known chain-type power transmission device. The chain 54 functions as a power transmission member capable of transmitting power from the engine 12 side to the front wheel 14 side.

[0015] The case 40 is made of, for example, an aluminum alloy casting and comprises a first case member 42 and a second case member 44. The first case member 42 and the second case member 44 correspond to the "multiple case members" in the present invention. The first case member 42 is a bottomed cylindrical shape with an opening on one side (= the second case member 44 side) in the direction of the first axis C1. The second case member 44 is a bottomed cylindrical shape with an opening on the other side (= the first case member 42 side) in the direction of the first axis C1. The first case member 42 has a fastening surface 42a on the outer circumference of its opening, and a plurality of fastening holes 42b are provided on the fastening surface 42a. The second case member 44 has a fastening surface 44a on the outer circumference of its opening, and a plurality of fastening holes 44b are provided on the fastening surface 44a. The fastening surface 42a of the first case member 42 and the fastening surface 44a of the second case member 44 are surfaces facing each other. When the fastening surface 42a of the first case member 42 and the fastening surface 44a of the second case member 44 are facing each other and aligned, the multiple fastening holes 42b and multiple fastening holes 44b are provided at corresponding positions. With the fastening surfaces 42a and 44a aligned, the first case member 42 and the second case member 44 are fastened together by bolts 70 that pass through the multiple fastening holes 42b and multiple fastening holes 44b, respectively. The surfaces where the fastening surfaces 42a and 44a face each other and align are the mating surfaces 46. In this way, the first case member 42 and the second case member 44 are fastened together at the mating surfaces 46.

[0016] Figure 2 is a perspective view of an example of the protector 60. The "protector 60" corresponds to the "protective member" in this invention.

[0017] Protector 60 has a stronger [N / m] than Case 40. 2 It is made of a material with high durability, such as steel. The protector 60 has a protective part 60p and a support part 60s, which are made of a plate-like body that has been bent. For example, the protective part 60p and the support part 60s are bent 90 degrees from each other. The protective part 60p is a part provided to protect the chain 54 from damaging the case 40. Specifically, the protective part 60p is a part that receives the impact of a broken chain 54 before it collides with the inner wall surface 40i of the case 40, which will be described later. The support part 60s is a part provided to position the protective part 60p of the protector 60 in a predetermined position. The "predetermined position" will be described later. The support part 60s is provided with a through hole 60h for fixing the support part 60s of the protector 60 to the mating surface 46 of the case 40.

[0018] Figure 3 illustrates the attachment of the protector 60 to the case 40, and is a schematic diagram of the cross section along the cutting line III-III shown in Figure 1, viewed in the direction of the arrow. Figure 3 shows the completed assembly state in which the sprocket 50, sprocket 52, and chain 54 are assembled inside the case 40, and the protective part 60p of the protector 60 is positioned in the predetermined location, with the second case member 44 not shown.

[0019] For example, if the driving torque [N·m] from sprocket 50 to sprocket 52 changes from a no-input state to an input state via chain 54, the chain 54 around the driven sprocket 52 is pulled. This can cause the chain 54 to lift away from the sprocket 52, resulting in a so-called gear skip where the chain 54 and sprocket 52 no longer mesh. This can cause excessive tension on the chain 54, potentially leading to the chain 54 breaking, and the broken chain 54 colliding with the inner wall surface 40i of the case 40, potentially damaging the case 40.

[0020] The protector 60 is fastened together with, for example, the first case member 42 and the second case member 44 by bolts 70. Specifically, the protector 60 is fastened to the mating surface 46 by bolts 70 that commonly penetrate through the fastening hole 42b of the first case member 42, the through hole 60h provided in the support portion 60s of the protector 60, and the fastening hole 44b of the second case member 44. Preferably, when the first case member 42, the support portion 60s of the protector 60, and the second case member 44 are fastened together by bolts 70, the shapes of the first case member 42, the support portion 60s of the protector, and the second case member 44 are such that no gap occurs at the mating surface 46. Also, an engaging portion that engages with the support portion 60s to position the protector 60 is provided on the first case member 42 or the second case member so that the protection portion of the protector 60 is disposed at a "predetermined position". The protector 60 is provided between a portion where the chain 54 separates from the sprocket 52 when driving torque for forward travel is transmitted from the sprocket 50 to the sprocket 52, and the inner wall surface 40i. The "portion where the chain 54 separates from the sprocket 52" is a portion where the chain 54 is likely to break due to gear jump when the driving torque for forward travel from the sprocket 50 to the sprocket 52 changes from a non-input state to an input state via the chain 54. The space between the portion where the chain 54 separates from the sprocket 52 when driving torque for forward travel is transmitted from the sprocket 50 to the sprocket 52 and the inner wall surface 40i is the "predetermined position" where the protection portion 60p of the aforementioned protector 60 is disposed. Also, preferably, the "predetermined position" is a position where the chain does not collide with the protection portion 60p when no gear jump occurs when the driving torque for forward travel from the sprocket 50 to the sprocket 52 changes from a non-input state to an input state via the chain 54.

[0021] According to this embodiment, (a) in case 40, a first case member 42 and a second case member 44, which are a plurality of case members, are fastened at mating surface 46; (b) when driving torque for forward travel is transmitted from sprocket 50 to sprocket 52, a protector 60 for suppressing damage to case 40 is provided between a portion where chain 54 separates from sprocket 52 in chain 54 and inner wall surface 40i; (c) protector 60 is fastened to mating surface 46 with bolts 70. Thus, when a protector 60 for suppressing damage to case 40 is provided between inner wall surface 40i and chain 54, the distance between inner wall surface 40i and chain 54 can be shortened as compared to the case where protector 60 is not provided. Thereby, an increase in the size of transfer 22 is suppressed.

[0022] Note that what has been described above is an embodiment of the present invention, and the present invention can be implemented in various modified and improved forms based on the knowledge of those skilled in the art without departing from the gist thereof.

[0023] In the foregoing embodiment, the “predetermined position” where the protection portion 60p of the protector 60 is disposed is in a mode between a portion where the chain 54 separates from the sprocket 52 in the chain 54 and the inner wall surface 40i when driving torque for forward travel is transmitted from the sprocket 50 to the sprocket 52. However, the present invention is not limited to this mode. For example, the “predetermined position” may be in a mode between a portion where the chain 54 separates from the sprocket 52 in the chain 54 and the inner wall surface 40i when driving torque for both forward and reverse travel is transmitted from the sprocket 50 to the sprocket 52.

Explanation of Reference Numerals

[0024] 22: Transfer, 40: Case, 40i: Inner wall surface, 42: First case member (a plurality of case members), 44: Second case member (a plurality of case members), 46: Mating surface, 54: Chain, 60: Protector (protection member), 70: Bolt

Claims

[Claim 1] A transfer comprising a case and a chain which is a power transmission member housed within the case, The aforementioned case is formed by fastening multiple case members together at the mating surfaces. A protective member is provided between the inner wall surface of the case and the chain to suppress damage to the case. The protective member is fastened to the mating surface with bolts. A transfer device characterized by the following features.

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