JP2015135144A - power transmission shaft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power transmission shaft that hardly rusts.SOLUTION: A power transmission shaft comprises: a first shaft 41 and a second shaft 42 that transmit power by rotating; and a covering layer 10A that is formed by shrinking a heat-shrinkable tube and covers outer peripheral surfaces of the first shaft 41 and a second shaft 42; and a bonding layer 21 that bonds the first shaft 41, the second shaft 42, and the covering layer 10A. In the heat-shrinkable tube, through-holes 11 that penetrate the inside and outside and release air from the inside of the heat-shrinkable tube to the outside at the time of shrinkage are formed.

Description

  The present invention relates to a power transmission shaft.

  A propulsion shaft (power transmission shaft, propeller shaft) mounted on the vehicle extends in the front-rear direction and is mounted on the rear side of the vehicle with power generated by a prime mover mounted on the front side of the vehicle and then decelerated by the transmission. It is transmitted to the final reduction gear. That is, the front end of the propulsion shaft is connected to the transmission via the first joint, and the rear end of the propulsion shaft is connected to the final reduction gear via the second joint.

  Such a propulsion shaft is normally rotatably supported under the floor panel of the vehicle, a cover is not disposed below the propulsion shaft, and the propulsion shaft faces the road surface. Therefore, there is a risk that the propulsion shaft will be splashed with muddy water from the front wheels, and rust will be generated on the propulsion shaft. Therefore, a method for forming a rust-preventing coating film on the surface of the propulsion shaft with a rust-preventing paint is known.

  However, if the pebbles or snow melting agent bounced up from the front wheels directly hit the propulsion shaft and the rust-proof coating is damaged, rust may be generated from the damaged portion.

  Therefore, a technique has been proposed in which a heat-shrinkable tube is contracted outside the propulsion shaft and a coating layer of about 0.2 to 0.4 mm is provided (see Patent Document 1). The covering layer and the propulsion shaft are bonded with an adhesive layer.

JP 2013-185675 A

  However, if a heat shrinkable tube is coated on a shaft with a large diameter such as a propulsion shaft, the amount of heat that heats the heat shrinkable tube is consumed by the temperature rise of the propulsion shaft, causing the heat shrinkable tube to contract and soften the adhesive layer. As a result, air may remain between the heat shrinkable tube and the propulsion shaft, and an air layer may be formed. Then, if the pebbles or snow melting agent that bounces up the front wheels directly hit the propeller shaft in the portion where the air layer is formed in this way, the coating layer may be broken and peeled off from the propeller shaft, and rust may be generated. is there.

  Therefore, an object of the present invention is to provide a power transmission shaft that hardly generates rust.

  As means for solving the above-mentioned problems, the present invention provides a power transmission member that transmits power by rotating and a coating layer that is formed by contraction of a heat-shrinkable tube and covers an outer peripheral surface of the power transmission member. And an adhesive layer for adhering the power transmission member and the coating layer, and a through hole is formed in the heat shrinkable tube to penetrate inside and outside, and to release the air in the heat shrinkable tube to the outside during shrinkage. It is the power transmission shaft characterized by this.

  According to such a configuration, the heat shrinkable tube is formed with a through-hole penetrating the inside and the outside, so that the air in the heat-shrinkable tube passes through the through-hole when the heat-shrinkable tube is contracted by being heated. To escape outside the heat shrink tube.

  Thereby, air does not remain between the coating layer formed by shrinking the heat shrinkable tube and the power transmission member. That is, the coating layer does not lift from the power transmission member. Therefore, even if a collision object such as a pebble or a snow melting agent collides with the coating layer, the coating layer is not torn. Therefore, water such as muddy water does not enter the coating layer, and rust does not occur in the power transmission member.

  The power transmission shaft preferably includes a balance weight that is fixed to the outer peripheral surface of the power transmission member and adjusts a rotational balance of the power transmission member, and the covering layer covers the balance weight.

  According to such a configuration, since the coating layer covers the balance weight, rust does not occur even in the balance weight.

  ADVANTAGE OF THE INVENTION According to this invention, the power transmission shaft which cannot generate | occur | produce rust easily can be provided.

It is a top view of the propulsion shaft concerning this embodiment. FIG. 3 is a cross-sectional view of the propulsion shaft according to the present embodiment, corresponding to a cross section taken along line X1-X1 in FIG. It is a top view of the propulsion shaft concerning a modification.

  An embodiment of the present invention will be described with reference to FIGS.

≪Composition of propulsion shaft≫
A propulsion shaft 100 (propeller shaft, power transmission shaft) according to the present embodiment shown in FIG. 1 is mounted on an FF-based four-wheel drive vehicle (vehicle), and a transmission (not shown) disposed on the front side of the vehicle. ) Is transmitted to a final reduction gear (not shown) disposed on the rear side of the vehicle. The propulsion shaft 100 extends under the floor panel in the front-rear direction and in the horizontal direction, and rotates about the rotation axis O1. That is, the propulsion shaft 100 faces the road surface, and does not include a cover or the like that protects against the pebbles and the like that the front wheels are flipped up. Note that the transmission shifts the power output from the internal combustion engine (prime mover) disposed under the hood on the front side of the vehicle.

  The propulsion shaft 100 has a two-piece structure (a two-part structure), and includes a first shaft 41 on the front side, a second shaft 42 on the rear side, and a constant velocity joint 50 that connects the first shaft 41 and the second shaft 42. The intermediate bearing unit 60 that supports the propulsion shaft 100 rotatably with respect to the vehicle body in the middle in the front-rear direction, the balance weight 71 and the balance weight 72, the coating layer 10A and the coating layer 10B, and the adhesive layer 21 are provided. Yes.

<First axis>
The first shaft 41 is a power transmission member that transmits power by rotating. In the present embodiment, the first shaft 41 is made of metal and has a cylindrical shape. An antirust coating film is formed on the outer peripheral surface of the first shaft 41 and the outer peripheral surface of the second shaft 42.

The front end of the first shaft 41 is connected to the output shaft of the transmission via a first joint 110 (cross shaft joint). Specifically, a stub yoke 111 constituting the first joint 110 is joined to the front end of the first shaft 41.
An outer ring member 51 described later is joined to the rear end of the first shaft 41.

<Second axis>
The second shaft 42 is a power transmission member that transmits power by rotating. In the present embodiment, the second shaft 42 is made of metal and has a cylindrical shape.

A rod-like stub shaft 43 is joined to the front end of the second shaft 42. The front end of the stub shaft 43 is inserted into an inner ring member 52 described later, and is splined to the inner ring member 52.
The rear end of the second shaft 42 is connected to the input shaft of the final reduction gear through a second joint 120 (cross shaft joint). Specifically, a stub yoke 121 constituting the second joint 120 is joined to the end of the second shaft 42.

<Constant velocity joint>
In the present embodiment, the constant velocity joint 50 is a tripod type. That is, the constant velocity joint 50 is fixed to the rear end of the first shaft 41 and is fixed to the outer ring member 51 (outer race) having three grooves formed on the inner peripheral surface thereof and the front end of the stub shaft 43. And an inner ring member 52 that moves in the outer ring member 51 in the axial direction.
However, the constant velocity joint 50 is not limited to the tripod type, and may be a double offset type, a lebro type, or a bar field type. In addition, the propulsion shaft 100 may not include the constant velocity joint 50, and the first shaft 41 and the second shaft 42 may be connected by a cross shaft joint.

<Intermediate bearing unit>
The intermediate bearing unit 60 is a unit that rotatably supports the stub shaft 43 with respect to the vehicle body. The intermediate bearing unit 60 includes a bearing 61 fitted on the stub shaft 43, an annular and rubber mount 62 that holds the bearing 61 from the outside, and a bracket 63 that holds the mount 62 and is fixed to the floor panel (vehicle body). And.

<Balance weight>
The two balance weights 71 are metal weights that are fixed to the outer peripheral surface of the first shaft 41 and adjust the rotational balance of the propulsion shaft 100. The balance weight 72 is a metal weight that is fixed to the outer peripheral surface of the second shaft 42 and adjusts the rotational balance of the propulsion shaft 100. The balance weights 71 and 72 have a plate shape and are fixed to the first shaft 41 and the second shaft 42 by resistance welding or the like, respectively. In addition, when fixing by resistance welding, after fixing balance weight 71 grade | etc., By resistance welding, balance weight 71 and its front-and-back part are rust-proof-coated.

<Coating layer>
The covering layer 10 </ b> A is a resin layer that covers the entire outer peripheral surface of the first shaft 41 including the outer peripheral surface of the balance weight 71. Thereby, muddy water etc. do not adhere to the 1st axis | shaft 41, and the 1st axis | shaft 41 is prevented from generating rust. In addition, since 10 A of coating layers are the structures which coat | cover the whole 1st axis | shaft 41, the antirust coating to the 1st axis | shaft 41 can also be abbreviate | omitted.

  The covering layer 10A is a layer formed by heating and shrinking a resin heat shrinkable tube (not shown) extrapolated to the first shaft 41, and has a thickness of 0.2 to 0.4 mm, for example. It is. The resin forming the heat-shrinkable tube (covering layer 10A) is, for example, a highly heat-resistant fluororesin or polyolefin resin, and more specifically polyvinylidene fluoride.

The covering layer 10 </ b> B is a resin layer that covers a portion that is in front of the balance weight 72 and that is likely to collide with stones and the like repelled by the front wheel on the second shaft 42. Thereby, the rust preventive coating film of the 2nd axis | shaft 42 is not damaged by stone repelling etc., and a rust preventive paint film is protected.
The coating layer 10B is a layer formed by heating and contracting a resin heat-shrinkable tube (not shown) extrapolated to the second shaft 42, similarly to the coating layer 10A.

<Coating layer-through hole>
A plurality of through holes 11 penetrating the inside and outside in the radial direction are formed in the coating layer 10A and the coating layer 10B. A plurality of through-holes 11 penetrating the inside and outside of the heat-shrinkable tube before contraction forming the coating layer 10A and the coating layer 10B are also formed.

  When the heat-shrinkable tube is contracted, the plurality of through holes 11 allow the air in the heat-shrinkable tube, that is, the air between the heat-shrinkable tube and the first shaft 41 or the second shaft 42 to be outside the radial direction of the heat-shrinkable tube. Air vent hole for escape.

  The plurality of through holes 11 are formed in a plurality of stages in the axial direction (front-rear direction), and are formed in a plurality of rows at equal intervals in the circumferential direction. That is, the plurality of through holes 11 are formed in the entire coating layer 10A and coating layer 10B (heat shrinkable tube) so that air does not remain in the coating layer 10A and coating layer 10B. The size, number, and axial / circumferential positions of the through-holes 11 are appropriately determined according to the diameters and axial lengths of the first shaft 41 and the second shaft 42.

<Adhesive layer>
The adhesive layer 21 is a layer for adhering the first shaft 41 and the coating layer 10A, and the second shaft 42 and the coating layer 10B, and is formed by curing the adhesive. For example, the adhesive layer 21 is formed by curing an adhesive containing nitrite, and the thickness thereof is, for example, 0.2 to 0.4 mm. Thus, since the adhesive layer 21 adheres the first shaft 41 or the second shaft 42 and the coating layer 10A, the coating layer 10A is in the axial direction with respect to the first shaft 41 or the second shaft 42 and There is no deviation in the circumferential direction.

  The adhesive layer 21 is also formed on the radially inner side of the through hole 11, and part of the adhesive layer 21 enters the through hole 11 and closes the through hole 11. Thereby, muddy water or the like does not enter the coating layer 10A and the coating layer 10B through the through hole 11. Therefore, the first shaft 41 and the second shaft 42 do not generate rust and have high corrosion resistance.

  Furthermore, since the covering layer 10A is in close contact with the entire outer peripheral surface of the first shaft 41 and the like via the adhesive layer 21, the covering layer 10A reduces the radiation sound from the first shaft 41 and the like due to the mass effect of the adhesive layer 21. it can. Thereby, in the 1st axis | shaft 41 grade | etc., In order to attenuate a radiation sound, the paper damper currently inserted in the propulsion axis | shaft can also be abbreviate | omitted.

≪Method for forming coating layer≫
A method for forming the coating layer 10A will be described.
The first shaft 41 and the second shaft 42 are connected via a constant velocity joint 50. A stub yoke 111 is joined to the front end of the first shaft 41, and a stub yoke 121 is joined to the rear end of the second shaft 42. An intermediate bearing unit 60 is attached to the stub shaft 43.

  The propulsion shaft 100 has its rotational balance adjusted by a rotational balance adjuster, a balance weight 71 is fixed to the outer peripheral surface of the first shaft 41, and a balance weight 72 is fixed to the outer peripheral surface of the second shaft 42. .

  Next, a cylindrical heat-shrinkable tube for forming the coating layer 10A is placed on the first shaft 41, and a cylindrical heat-shrinkable tube for forming the coating layer 10B is placed on the second shaft 42. Since the heat-shrinkable tube is before heating, that is, before shrinkage, it has a larger diameter than the first shaft 41 and the second shaft 42, and between the heat-shrinkable tube and the first shaft 41 and the second shaft 42, A gap is formed.

  Moreover, the adhesive agent for forming the contact bonding layer 21 is apply | coated to the internal peripheral surface of a heat contraction tube.

  Next, the heat shrinkable tube is heated and shrunk to form the coating layer 10A and the coating layer 10B. In this case, the air between the heat-shrinkable tube and the first shaft 41 or the second shaft 42 passes through the plurality of through holes 11 and escapes to the radially outer side (outside) of the heat-shrinking tube. That is, air does not bite between the coating layer 10 </ b> A and the first shaft 41 and between the coating layer 10 </ b> B and the second shaft 42. In parallel with this, the adhesive is cured to form the adhesive layer 21 and close the through hole 11.

  Thus, air does not remain between the coating layer 10A and the first shaft 41, and between the coating layer 10B and the second shaft 42, and the coating layer 10A does not float from the first shaft 41, and the coating layer 10B. However, it does not lift from the second shaft 42. That is, the entire coating layer 10 </ b> A is in good contact with the first shaft 41 through the adhesive layer 21, and the entire coating layer 10 </ b> B is in close contact with the second shaft 42 through the adhesive layer 21. Further, since the coating layer 10A covers the entire first shaft 41, it is not necessary to form a rust-preventing coating film with a rust-preventing paint.

≪Modification≫
As mentioned above, although one Embodiment of this invention was described, this invention is not limited to this, For example, you may change as follows.

  In the above-described embodiment, the configuration in which the coating layer 10A covers the entire first shaft 41 including the balance weight 71 is exemplified. However, for example, as illustrated in FIG. The balance weight 71 and its front and rear portions may be covered.

According to such a configuration, the coating layer 10C partially covers the first shaft 41 including the balance weight 71 while reducing the heating amount of the heat-shrinkable tube required for forming the coating layer 10C. Intrusion of muddy water or the like into the joint gap between 71 and the first shaft 41 is prevented, and the corrosion resistance is improved. That is, the anticorrosion paint does not easily enter the gap between the balance weight 71 and the first shaft 41 and the anticorrosion coating film is difficult to form. Will improve.
Further, also on the second shaft 42, the coating layer 10D covers the balance weight 72 and its front and rear portions.

10A, 10A Covering layer 11 Through hole 21 Adhesive layer 41 First shaft (power transmission member)
42 Second shaft (power transmission member)
50 Constant velocity joint 71 Balance weight 100 Propulsion shaft (power transmission shaft)

Claims (2)

A power transmission member that transmits power by rotating;
A heat-shrinkable tube is formed by shrinking, and a coating layer that covers the outer peripheral surface of the power transmission member;
An adhesive layer for bonding the power transmission member and the coating layer;
With
A power transmission shaft, wherein a through hole is formed in the heat shrinkable tube so as to penetrate the inside and outside of the heat shrinkable tube and allow the air in the heat shrinkable tube to escape to the outside during shrinkage. The balance is fixed to the outer peripheral surface of the power transmission member, and includes a balance weight for adjusting the rotational balance of the power transmission member,
The power transmission shaft according to claim 1, wherein the coating layer covers the balance weight.

Images