Steering intermediate shaft

Abstract

The utility model relates to a steering intermediate shaft, and belongs to the technical field of automobile parts. The steering intermediate shaft comprises a spline pipe and a spline shaft, and the spline shaft is in sliding insertion connection with the spline pipe through a spline; a center counter bore is formed in the end face of the spline shaft, and a spline of the spline shaft is coated with a resin layer. An air hole is formed in a port of the center counter bore. According to the steering intermediate shaft, resin can be blocked through gas in the gas holes, the resin is prevented from blocking the center counter bore, and therefore it is guaranteed that the spline shaft is accurately and conveniently assembled. The spline of the spline shaft with the normal size cannot be inserted into the spline tooth groove with the small root circle diameter, the size of the spline of the spline shaft is detected through the spline tooth groove with the small root circle diameter, it is guaranteed that the spline of the spline shaft can be exactly inserted into the spline of the spline pipe, and therefore the uniqueness of assembly is guaranteed. The problems that due to the fact that an existing steering intermediate shaft is coated with a resin layer, a center counter bore is prone to being blocked, and a gap between a spline pipe and a spline of a spline shaft is not easy to control are solved.

Description

Technical Field

[0001] The utility model relates to a steering intermediate shaft and belongs to the technical field of automobile parts. Background Art

[0002] The steering intermediate shaft is the middle part connecting the steering column and the steering gear, which includes a spline shaft and a spline tube. The spline shaft is connected to the spline tube by sliding insertion through splines. Through the relative sliding of the spline shaft and the spline tube, the distance between the end of the spline shaft and the end of the spline tube can be adjusted, thereby adjusting the height of the steering wheel so that the height of the steering wheel can adapt to the height of the driver to ensure driving comfort.

[0003] In order to ensure that the splines between the spline tube and the spline shaft are not easy to collide with each other and generate noise when the spline tube drives the spline shaft to rotate, a resin layer is generally coated on the spline of the spline shaft, and the gap between the spline shaft and the spline of the spline tube is filled with the resin layer, so as to avoid collision between the splines, effectively reduce the noise during steering, and the noise during the process of adjusting the steering wheel height; at the same time, the spline is protected by the resin layer. However, after the resin layer is coated, the resin layer is easy to block the center countersunk hole on the end face of the spline shaft. After the center countersunk hole is blocked, it is not convenient to position the spline shaft when assembling the spline shaft, resulting in inconvenience in assembly; at the same time, although the coated resin layer is very thin (5-40μm), it still has thickness, so when assembling the spline shaft, it is necessary to select a spline tube with a larger tooth width and root circle, but when the tooth width and root circle are too large, the gap between the spline of the spline tube and the spline shaft will be too large; the gap between the spline of the spline tube and the spline shaft is not easy to control. Therefore, it is necessary to improve the steering intermediate shaft to solve the above problems. Summary of the invention

[0004] The utility model aims to provide a steering intermediate shaft which is not easy to block the central countersunk hole when coating the resin layer and can ensure that the spline meshing clearance between the spline shaft and the spline tube is moderate.

[0005] The technical solution of the utility model is:

[0006] A steering intermediate shaft comprises a spline tube and a spline shaft, wherein the spline shaft is slidably plug-in connected to the spline tube via splines; a central countersunk hole is arranged on the end face of the spline shaft, and a resin layer is coated on the splines of the spline shaft; the characteristic is that an air hole is arranged at the end of the central countersunk hole.

[0007] The difference between the number of spline teeth of the spline shaft and the number of spline teeth of the spline tube is 1.

[0008] The root circle diameter of one tooth groove of the spline of the spline tube is smaller than the root circle diameters of the other tooth grooves of the spline of the spline tube.

[0009] The beneficial effects of the utility model are:

[0010] The steering intermediate shaft can prevent the resin from entering the central countersunk hole through the air holes when the resin layer is coated, thereby preventing the resin from clogging the central countersunk hole. The central countersunk hole can be used to position the spline shaft during assembly, ensuring that the spline shaft is accurately and conveniently assembled. The root circle diameter of one of the splines of the spline tube is smaller than the root circle diameter of the other splines of the spline tube, so that the spline of the normal size of the spline shaft cannot be inserted into the spline tooth groove with a small root circle diameter. The spline size (including the thickness of the resin layer) of the spline shaft is detected through the spline tooth groove with a small root circle diameter during assembly of the spline shaft, ensuring that the spline of the spline shaft can be just inserted into the spline of the spline tube, thereby ensuring the uniqueness of the assembly. The problem that the existing steering intermediate shaft is easily blocked in the central countersunk hole due to the coating of the resin layer and the gap between the spline of the spline tube and the spline shaft is difficult to control is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a cross-sectional schematic diagram of the utility model;

[0012] Figure 2 It is a longitudinal cross-sectional schematic diagram of the utility model;

[0013] Figure 3 It is a structural schematic diagram of the spline tube of the utility model;

[0014] Figure 4 It is a structural schematic diagram of a spline shaft of the utility model.

[0015] In the figure: 1. spline tube, 2. spline shaft, 3. spline, 4. center countersunk hole, 5. air hole, 6. position where the spline shaft lacks a spline tooth, 7. position where the root circle diameter of the spline tube tooth groove is small. DETAILED DESCRIPTION

[0016] The steering intermediate shaft comprises a spline tube 1 and a spline shaft 2. The spline shaft 2 is connected to the spline tube 1 by a sliding insertion through a spline 3, so that the spline tube 1 and the spline shaft 2 can slide relative to each other in the axial direction through the spline 3, and the spline tube 1 can drive the spline shaft 2 to rotate through the spline 3. A center counterbore 4 is provided on the end surface of the spline shaft 2, so that the center counterbore 4 is used for positioning, thereby facilitating the positioning of the spline shaft 2, thereby facilitating the processing and assembly of the spline shaft 2. The spline 3 of the spline shaft 2 is coated with a resin layer, so that the collision noise and sliding noise between the spline 3 of the spline shaft 2 and the spline 3 of the spline tube 1 are eliminated through the resin layer, and the spline 3 of the spline shaft 2 is protected at the same time.

[0017] The port of the center countersunk hole 4 is provided with an air hole 5. When the spline shaft 2 is coated with a resin layer, the end of the air hole 5 of the spline shaft 2 is vertically inserted downward into the configured resin solution. After the spline shaft 2 is inserted, due to the presence of air in the air hole 5, the resin solution will not enter the air hole 5 under the action of the surface tension of the air in the air hole 5 and the resin solution, and further the resin solution will not enter the center countersunk hole 4, thereby ensuring that after the resin solidifies, the center countersunk hole 4 of the spline shaft 2 will not be blocked. After the spline 3 of the spline shaft 2 is immersed in the resin solution for 10 seconds, the spline shaft 2 is lifted up, and the spline shaft 2 is placed above the resin solution for 1 minute to allow the excess resin solution on the spline 3 of the spline shaft 2 to drip off, and the spline shaft 2 coated with the resin is sent into an oven to dry the resin to form a resin layer.

[0018] The difference between the number of spline teeth of the spline shaft 2 and the number of spline teeth of the spline tube 1 is 1, that is, the spline 3 of the spline shaft 2 lacks one tooth. The lack of one tooth in the spline 3 of the spline shaft 2 can form a gas flow channel between the spline tube 1 and the spline shaft 2, so that the inside of the spline tube 1 can be connected with the outside through the gas flow channel. Therefore, when the spline shaft 2 and the spline tube 1 slide relative to each other, it is not easy to form air resistance between the spline tube 1 and the spline shaft 2, thereby effectively reducing the sliding resistance between the spline tube 1 and the spline shaft 2.

[0019] The root circle diameter of one of the tooth grooves of the spline of the spline tube 1 is smaller than the root circle diameter of the other tooth grooves of the spline of the spline tube 1, so as to detect the spline of the spline shaft 2 through the tooth groove with a smaller root circle diameter of the spline tube 1:

[0020] When the splines of the spline shaft 2 can be normally inserted into the tooth grooves of other splines of the spline tube 1, but cannot be inserted into the tooth grooves with a smaller root circle diameter of the spline tube 1, the clearance between the splines of the spline shaft 2 and the splines of the spline tube 1 is within the process requirement range, and the spline shaft 2 and the spline tube 1 are unique;

[0021] When the splines of spline shaft 2 can be normally inserted into the tooth grooves of other splines of spline tube 1, and can be inserted into the tooth grooves with smaller root circle diameter of spline tube 1, the gap between the splines of spline shaft 2 and the splines of spline tube 1 is too large, and spline shaft 2 and spline tube 1 are not unique. Replace spline tube 1 to match it with spline shaft 2 again.

[0022] At the same time, since the splines of the spline shaft 2 cannot be inserted into the tooth grooves with small root circle diameters of the spline tube 1, the adjacent spline teeth on both sides of the tooth grooves with small root circle diameters of the spline tube 1 can only be inserted at the position where the spline 3 of the spline shaft 2 lacks a tooth, so that the direction of the spline shaft 2 is fixed relative to the direction of the spline tube 1, and the spline shaft 2 and the spline tube 1 are unique in the assembly direction.

[0023] When assembling the steering intermediate shaft, a resin layer is applied to the spline 3 of the spline shaft 2. After the resin layer of the spline shaft 2 is dried, the spline of the spline shaft 2 is tried to be inserted into the tooth groove with a small tooth root circle diameter of the spline tube 1. When the spline of the spline shaft 2 cannot be inserted into the tooth groove with a small tooth root circle diameter of the spline tube 1, the spline shaft 2 is rotated, and the position where the spline 3 of the spline shaft 2 lacks a tooth is aligned with the adjacent spline teeth on both sides of the tooth groove with a small tooth root circle diameter of the spline tube 1 and inserted into the spline 3 of the spline tube 1. During the insertion of the spline shaft 2, the gas in the spline tube 1 is discharged outward from the gas channel formed by the position where the spline 3 of the spline shaft 2 lacks a tooth, so that the pressure inside and outside the spline tube 1 is balanced, the gas resistance is reduced, and the insertion of the spline shaft 2 is convenient.

[0024] The air holes of the steering intermediate shaft can prevent the resin from entering the center counterbore 4 through the bubbles formed by the gas in the air holes 5 when the resin layer is coated, thereby preventing the resin from clogging the center counterbore 4. The center counterbore 4 can be used to position the spline shaft 2 when it is assembled, ensuring that the spline shaft 2 is accurately and conveniently assembled. The root circle diameter of one of the splines of the spline tube 1 is smaller than the root circle diameter of the other splines of the spline tube, so that the splines of the spline shaft 2 of normal size cannot be inserted into the spline tooth grooves with small root circle diameters. The spline tooth grooves with small root circle diameters are used to detect the size of the splines of the spline shaft when the spline shaft is assembled, ensuring that the splines of the spline shaft 2 can be just inserted into the splines of the spline tube, thereby ensuring the uniqueness of the assembly. The problem that the center counterbore is easily blocked and the gap between the spline tube and the spline shaft is difficult to control due to the coating of the resin layer of the existing steering intermediate shaft is solved.

Claims

1. A steering intermediate shaft, comprising a spline tube (1) and a spline shaft (2), wherein the spline shaft (2) is connected to the spline tube (1) by sliding insertion via a spline (3); a central countersunk hole (4) is provided on the end surface of the spline shaft (2), and a resin layer is coated on the spline (3) of the spline shaft (2); the characteristics are: An air hole (5) is provided at the end of the central counterbore (4).

2. A steering intermediate shaft according to claim 1, characterized in that: The difference between the number of spline teeth of the spline shaft (2) and the number of spline teeth of the spline tube (1) is (1).

3. A steering intermediate shaft according to claim 2, characterized in that: The root circle diameter of one of the tooth grooves of the spline of the spline tube (1) is smaller than the root circle diameters of the other tooth grooves of the spline of the spline tube (1).

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