JP3851101B2 - Spline processing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a spline processing method for forming a resin layer having a predetermined thickness on a spline shaft such as a universal joint.
[0002]
[Prior art]
The spline surface of a spline shaft such as a universal joint is coated with a resin layer of nylon resin or the like for the purpose of silencing, wear resistance, reducing sliding load, and the like. For the formation of this resin layer, a fluid immersion method is generally used. In this fluidized immersion method, first, the spline shaft 21 that has been subjected to the ground treatment such as shot blasting and primer is heated in a heating furnace. Next, as shown in FIG. 6, the resin powder 23 is dipped in a fluidized state by air 22 for a predetermined time. Thereby, the resin powder 23 adheres to the spline shaft 21 and is melted by heat, whereby a resin layer is formed.
[0003]
When the resin layer is formed by this fluidized immersion method, the degree of melting of the resin powder 23 depends on the heat capacity of the spline shaft, but the formed resin layer becomes non-uniform due to variations in the heat capacity. For this reason, after forming the film thickness of the resin layer to be thick (for example, about 500 μm) by the fluidized dipping method, it is finished to a predetermined film thickness (for example, about 200 to 300 μm) by broaching or cutting.
[0004]
In the conventional broaching process, first, as shown in FIG. 7, the center pin 28 provided on the front side holding jig 26 and the center pin 28 provided on the front side holding jig 26 and the center positioning tapered holes 30 and 31 provided at the axial centers of both end faces of the spline shaft 21 are provided. The spline shaft 21 is fixed by fitting the center pin 29 provided on the back side holding jig 27 and sandwiching the spline shaft 21 by the front side holding jig 26 and the back side holding jig 27.
[0005]
The spline shaft 21 thus fixed is moved in the direction of the broach die 25 together with the holding jigs 26 and 27, and the broach die 25 having an inner peripheral tooth surface similar to the tooth shape of the spline shaft 21 and having a predetermined amount larger. Through the inside. Thus, when the spline shaft 21 passes through the broach die 25, the resin layer formed thickly on the spline shaft 21 is scraped off by the broach die 25 and finished to a predetermined film thickness.
[0006]
[Problems to be solved by the invention]
By the way, as for the silencing effect by forming the resin layer on the spline shaft, it is generally advantageous that the resin layer is thicker. On the other hand, it is advantageous that the thickness of the resin layer is smaller with respect to the abrasion of the resin layer during sliding. FIG. 5 is a graph showing the relationship between the film thickness of the resin layer, the operating sound, and the wear amount investigated by the inventors of the present application. The operating sound is a coefficient value when the resin layer is not formed, and the wear amount is 100. The coefficient value is represented by 100 when a resin layer having a film thickness of 360 μm is formed. As shown in FIG. 5, in view of the silencing effect and durability, it was found that the most effective when the thickness of the resin layer is about 100 to 200 μm.
[0007]
However, since the conventional broaching process is performed only at the center position as described above, the teeth of the broach die 25 and the teeth of the spline shaft 21 do not accurately match in the circumferential direction. For this reason, when trying to finish the film thickness of the resin layer to 200 μm or less by the conventional broaching process, the film thickness of the resin layer differs on the left and right sides of the spline shaft teeth. It was.
[0008]
Moreover, when trying to finish the film thickness of the resin layer to 200 μm or less by, for example, cutting other than broaching, it is possible to ensure accuracy, but there is a problem that the processing cost increases.
The present invention has been proposed in view of the above circumstances, and it is possible to finish a resin layer formed on a spline surface of a spline shaft by a flow dipping method with high accuracy and low cost even if the film thickness is thin. An object of the present invention is to provide a spline processing method that can be used.
[0009]
[Means for Solving the Problems]
The present invention employs the following means in order to achieve the above object. That is, in a spline processing method in which a resin layer is formed on the surface of the teeth of the spline shaft by a flow dipping method, and then the resin layer is finished to a predetermined film thickness by broaching , both ends of the spline shaft are formed after the resin layer is formed. a centering taper hole provided on the surface axis center position, the circumferential positioning tapered hole located radially outward of the tapered bore for determining the center position with provided on at least one end face of the spline shaft, In the state where the positional relationship is determined so that the distance between the broaching-type teeth and the spline shaft teeth is uniform in the circumferential direction , the resin film is passed through the broaching mold. A method of uniformly finishing the thickness is employed (claim 1). According to such a method, the broaching-type teeth and the spline shaft teeth can be accurately aligned at a predetermined interval in the circumferential direction, so that the resin layer to be formed on the spline shaft is thin. Even if it exists, it becomes possible to finish a resin layer uniformly by broaching process with low processing cost.
[0010]
Moreover, it is preferable that the film thickness of the said resin layer is finished to 100-200 micrometers. In this case, the object of the silencing effect and the improvement of durability by covering the spline shaft with the resin layer can be most effectively achieved.
[0011]
Further, since the performing positioning with the centering taper hole and the circumferential positioning tapered bore of spline shaft, it is possible to position the spline shaft easily.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a side view for illustrating a broaching method in one embodiment of a spline processing method according to the present invention, and FIG. 2 is a front view and a side sectional view showing a spline shaft used in the present embodiment. FIG. 3 is a front view showing a broach mold used in the present embodiment. Hereinafter, the spline processing method will be described with reference to the drawings. In addition, since the fluid immersion method of the spline processing method of this Embodiment is the same as that of the past, it demonstrates using FIG.
[0013]
In the spline processing method of the present embodiment, first, the spline shaft 1 that has undergone the base treatment such as shot blasting or primer is heated in a heating furnace. As shown in FIG. 6, the spline shaft 1 is immersed in a fluid immersion tank 24 in which the resin powder 23 is fluidized by air 22 for a predetermined time. Thereby, the resin powder 23 adheres to the spline shaft 1 and is melted by heat, whereby the resin layer 7 is formed. Here, the resin layer 7 is formed thicker (for example, about 500 μm) than the required film thickness (for example, about 100 to 200 μm).
[0014]
Next, as shown in FIGS. 1 and 2, a center positioning taper hole 11 provided at the axial center of one end surface of the spline shaft 1 and a circumferential positioning taper provided radially outward from the axial center. A center pin 4 and a positioning pin 5 each having a tapered tip portion that matches each tapered hole provided in the front side holding jig 3 are fitted into the hole (positioning portion) 12. At the same time, a center pin 7 having a tapered tip portion that matches the taper hole provided in the back surface holding jig 6 is fitted into the center positioning taper hole 13 provided in the center of the axis of the other end surface of the spline shaft 1. Combine.
[0015]
As a result, as shown in FIG. 3, the broach die 2 and the spline shaft 1 having an inner peripheral tooth surface 2 a having a shape similar to the tooth shape of the spline shaft 1 and having a predetermined amount larger are aligned. Further, as shown in FIG. 4, the circumferential position of the spline shaft 1 is determined so that the circumferential distances S on both sides of the tooth 2 a of the broach die 2 and the tooth 1 a of the spline shaft 1 are equal. The spline shaft 1 is fixed by sandwiching the spline shaft 1 with the front side pressing jig 3 and the back side pressing jig 6.
[0016]
The spline shaft 1 fixed by the front-side holding jig 3 and the back-side holding jig 6 is moved in the direction of the broach die 2 together with the holding jigs 3 and 6 and passed through the broach die 2. When the spline shaft 1 passes through the broach die 2, the positioning pin 5 prevents the gap S between the teeth 2a of the broach die 2 and the teeth 1a of the spline shaft 1 shown in FIG. Then, the resin layer 7 formed thicker on the spline shaft 1 having the interval S or more is scraped off by the broach die 2 and finished to a predetermined film thickness.
[0017]
Since the spline shaft 1 is positioned using the center positioning tapered hole 11 and the circumferential positioning tapered hole 12 of the spline shaft 1 as described above, the teeth of the broach die 2 and the teeth of the spline shaft 1 are Even in the circumferential direction, it can be accurately matched at a predetermined interval. Thereby, even if the film thickness of the resin layer 7 which should be formed in the spline shaft 1 is about 100-200 micrometers, it becomes possible to finish a resin layer uniformly.
[0018]
In the present embodiment, the spline shaft 1 is moved together with the holding jig and passed through the broaching die 2. However, the present invention is not limited to this, for example, the broaching type with the spline shaft 1 fixed together with the holding jig. Processing may be performed by moving 2. In this embodiment, the spline shaft 1 is provided with one circumferential positioning taper hole 12. However, the present invention is not limited to this. For example, two or more circumferential positioning taper holes 12 are provided. Positioning may be performed.
[0019]
【The invention's effect】
As described above, in the spline processing method according to the present invention, after the resin layer is formed on the spline surface of the spline shaft by the flow dipping method, the spline shaft is based on the center positioning taper hole and the circumferential positioning taper hole. The resin layer is finished to a predetermined film thickness. Therefore, even when the film thickness of the resin layer to be formed on the spline shaft is thin, the resin layer can be uniformly finished by broaching at a low processing cost.
[0020]
Moreover, when finishing the film thickness of a resin layer to 100-200 micrometers, the objective of the silencing effect and durability improvement by coat | covering a spline shaft with a resin layer can be achieved most effectively.
[0021]
The center position of the spline shaft is determined by the center positioning taper hole provided at the center position of both end faces of the spline shaft, and the positioning portion of the spline shaft is used for positioning provided on at least one end face of the spline shaft. By using a tapered hole, the spline shaft can be easily positioned.
[Brief description of the drawings]
FIG. 1 is a side view showing a broaching method in an embodiment of a spline processing method according to the present invention.
FIGS. 2A and 2B are a front view and a side cross-sectional view showing a spline shaft used in an embodiment of a spline processing method according to the present invention. FIGS.
FIG. 3 is a front view showing a broach die used in an embodiment of the spline processing method according to the present invention.
FIG. 4 is an explanatory diagram showing a positional relationship between the teeth of the spline shaft and the broached teeth.
FIG. 5 is a graph showing the relationship between the film thickness of the resin layer formed on the spline shaft, the operating noise, and the wear amount.
FIG. 6 is an explanatory diagram for illustrating the formation of a resin layer by a fluid immersion method.
FIG. 7 is a side view for showing a conventional broaching process.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Spline shaft 2 Broach type | mold 3 Front side pressing jigs 4 and 7 Center pin 5 Positioning pin 6 Back side pressing jig 7 Resin layer 12 Positioning taper holes 11 and 13 Center positioning taper holes

Claims (2)

In the spline processing method of forming a resin layer on the tooth surface of the spline shaft by a flow dipping method and finishing the resin layer to a predetermined film thickness by broaching,
After formation of the resin layer, and a centering taper hole provided in both end faces axis center position of the spline shaft, the center position radially outer than a tapered hole decided together is provided on at least one end face of the spline shaft In the state where the positional relationship is determined so that the spacing between the teeth of the broaching die and the teeth of the spline shaft is uniform in the circumferential direction based on the circumferential positioning tapered hole located in the direction , the broaching die A spline processing method, wherein the film thickness of the resin layer is uniformly finished by passing the spline shaft .   The spline processing method according to claim 1, wherein the resin layer has a thickness of 100 to 200 μm.

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