KR20240070257A - Worm wheel mounting method on lifter housing in CVVD manufacturing process - Google Patents

Abstract

The present invention is a worm wheel alignment and supply system for mounting a worm wheel on a lifter housing of an automobile. The system includes a guide moving part and a worm wheel supply device that moves left and right by being driven by the guide moving part, and the worm wheel supply device includes a worm wheel. A worm wheel alignment and supply system comprising a worm wheel guide providing a passage for supply and mounting, the system including a guide bar inserted into the worm wheel guide to determine a fixed position of the worm wheel supply device, and a worm wheel mounting process using this system. commences.

Description

Worm wheel mounting method on lifter housing in CVVD manufacturing process}

The present invention relates to a method of mounting a worm wheel on a lifter housing during the CVVD manufacturing process.

A car's internal combustion engine generates power by taking fuel and air into the combustion chamber and burning them. When taking in air, the intake valve and exhaust valve are operated alternately by driving the camshaft. The optimal operation of the intake and exhaust valves varies depending on the rotational speed of the engine, and appropriate lift operation must be performed and the opening and closing timing of the valves must be adjusted accordingly. For this purpose, multiple valve driving cams were designed or continuously variable valve lift (CVVL) or continuously variable valve timing (CVVT) were developed, but they have the disadvantages of being complex in structure, difficult to control, and expensive.

Therefore, a continuous variable valve duration (CVVD) device that can immediately adjust the duration of the valve, that is, the time from opening to closing, according to the operating state of the engine has been developed and is being applied.

Patent No. 10-2020-0073858 discloses a CVVD device 10' mounted on the camshaft 30' of the engine 1' as shown in FIG. 1. The CVVD device 10' has a structure in which a pair of modules consisting of a lifter housing 90' mounted on a guide bracket 134' are connected to a control shaft 102', both ends of which are connected to a control worm 104'. It consists of A cap 40 and cams 71' and 72' are arranged on the camshaft 30', and lower portions of the cams 71' and 72' are connected to intake and exhaust valves (not shown).

Looking at the lifter housing 90' and related structures disclosed in the above patent, as shown in FIG. 2, between the two guide holes 94' in the center of the guide wall 92' on the upper part of the lifter housing 90'. A worm wheel (50') is mounted on the guide shaft (132'), which has threads (130') formed through the guide hole (94'), and the sliding holes (96) on both sides around the guide hole (94') are fastened to the guide shaft (132'). '), a sliding shaft 135' is fastened thereto. The control worm 104' meshes with the worm wheel 50'. Here, when the control worm 104' rotates by driving an actuator (not shown), the worm wheel 50' moves along the thread 130' of the guide shaft 132' and pushes the guide wall 92' to move the camshaft. (30') The relative position of the lifter housing 90' with respect to the central axis is changed, and the rotational speed of the cams 71' and 72' with respect to the cam shaft 30' is changed according to their phases.

In Patent Application No. 10-2021-0094329 on July 19, 2021, the applicant disclosed an assembly process in which the lifter housing and the guide bracket are combined and the guide shaft is aligned and combined without error while the worm wheel is mounted. During this assembly process, the worm wheel is manually or automatically installed in the central space between the guide walls.

However, the gap between the assembly of the worm wheel and lifter housing is 0.01 to 0.04 mm, so the worm wheel can be installed automatically without error only if the position of the lifter housing and the worm wheel supply part are accurate. This requires a precision jig to supply the worm wheel to the lifter housing assembly and an assembly method to align the position of the jig.

The purpose of the present invention is to provide a worm wheel supply and alignment system and a worm wheel installation method that enable a worm wheel to be accurately mounted on a lifter housing within an allowable tolerance range.

In order to achieve the above-mentioned object, the present invention is a worm wheel alignment and supply system for mounting a worm wheel on a lifter housing of an automobile. The system includes a guide moving part and a worm wheel supply device that moves left and right by driving the guide moving part, , The worm wheel supply device is formed with a worm wheel guide that provides a passage through which the worm wheel is supplied and mounted, and the system includes a guide bar inserted into the worm wheel guide to determine the fixed position of the worm wheel supply device. A worm wheel alignment and supply system. to provide.

The first side of the worm wheel guide may be sized to accommodate the thickness of the worm wheel, and the remaining second side may be sized to accommodate the outer diameter of the worm wheel extending in a direction perpendicular to the thickness of the worm wheel.

A taper may be formed at the top of the second side that slopes downward toward the center.

The first side of the guide bar is the same size or slightly smaller than the first side of the worm wheel guide, the second side is the same size or slightly smaller than the second side of the worm wheel guide, and the height of the guide bar is the same as that of the worm wheel guide. It is greater than the height of, and its lower end may be adjacent to or in contact with the mounting surface on which the worm wheel of the ritter housing is mounted.

The guide moving part includes a guide shaft whose end rod is coupled to the body of the worm wheel supply device, and the guide shaft can be operated by driving the guide moving part.

In addition, the present invention provides a method of mounting a worm wheel to a lifter housing of an automobile, the method comprising: mounting a worm wheel supply device on the lifter housing and inserting a guide bar into the worm wheel guide of the worm wheel supply device; Moving the worm wheel supply device to the left and right to fix the worm wheel supply position at a position where the worm wheel guide is in close contact with the guide bar; Retracting the guide bar and separating it from the worm wheel guide; and the step of pushing the worm wheel into the worm wheel guide and mounting it between the spaces of the vertical portion of the lifter housing.

The step of moving the worm wheel supply device may be a step of moving the worm wheel supply device left and right by operating a guide shaft connected to the worm wheel supply device.

According to the present invention, the worm wheel can be installed quickly and automatically by accurately mounting the worm wheel on the lift housing and satisfying the clearance conditions, thereby improving the assembly workability of CCVD products and reducing costs.

1 shows a conventional CVVD device;
Figure 2 is a view showing a lift housing and related members in the prior art;
Figure 3 is a perspective view showing a worm wheel before being mounted on an assembly of a lifter housing and a guide bracket according to an embodiment of the present invention;
Figure 4 is a perspective view showing the worm wheel in Figure 3 mounted;
Figure 5 is a view showing a pair of assemblies assembled with a lifter housing and a guide bracket aligned on a pallet installed on a stand and base;
Figure 6 is a plan view of the assembly on the right side of Figure 5 from above and along the direction of the dotted arrow;
Figure 7 is a cross-sectional view taken along the direction aa of Figure 6, showing the guide moving part together;
FIG. 8 is a cross-sectional view cut along the bb direction of FIG. 7, but the guide moving part is omitted;
Figure 9 is a flowchart explaining the worm wheel mounting process of the present invention step by step; and
FIGS. 10(a) and 10(b) are views corresponding to FIGS. 7 and 8, respectively, and are views showing the intermediate and final positions of the worm wheel during installation.

The purpose and effects of the present invention, and technical configurations for achieving them, will become clear by referring to the embodiments described in detail below along with the accompanying drawings. In describing the present invention, if it is determined that a detailed description of a known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description will be omitted.

Throughout the specification, when a part is said to “include” a certain element, this means that it may further include other elements rather than excluding other elements, unless specifically stated to the contrary. Meanwhile, in an embodiment of the present invention, each component, functional block, or means may be composed of one or more lower components.

Figure 3 is a perspective view showing the worm wheel (5) before being mounted on the assembly of the lifter housing (1) and the guide bracket (2) according to an embodiment of the present invention, and Figure 4 is a diagram showing the worm wheel (5) being mounted. This is a perspective view showing what has happened. In the drawing, the thickness direction, that is, the width direction of the outer circumference, based on the worm wheel 5, is indicated as the x-axis, the horizontal direction of the diameter of the worm wheel 5 perpendicular to the x-axis is indicated as the y-axis, and the height direction is indicated as the z-axis.

Referring to the two drawings together, the lifter housing 1 includes a circular ring 10 and a pair of vertical portions 14 having a through hole 12 integrally formed on the ring 10. . The vertical portions 14 face each other, and a worm wheel 5 is mounted between the facing spaces. A thread is machined on the outer circumference of the worm wheel (5). The guide bracket (2) is made of a massive body, and can be temporarily coupled to the lifter housing (1) with a slide shaft (not shown) as disclosed in Patent Application No. 10-2021-0094329.

The lifter housing 1 and the guide bracket 2 are only shown as examples, and as long as the lifter housing 1 has a worm wheel 5 mounting structure, its shape, structure and size are not limited to those shown.

In Figure 5, a pair of assemblies consisting of a lifter housing (1) and a guide bracket (2) are aligned and positioned on a pallet installed on a stand and base.

The worm wheel alignment and supply system (S) of the present invention includes a guide moving part 100 and a worm wheel supply device 200. The assembly on the right side of Figure 5 is equipped with a worm wheel supply device 200, which is a feature of the present invention. The guide moving part 100 connected to the worm wheel supply device 200 is not shown for convenience of explanation. At the center of the worm wheel supply device 200, a space for mounting the worm wheel 5 and an open worm wheel guide 204 are formed elongated in the height direction. As will be described later, after the guide bar 300 enters the worm wheel guide 204 and aligns the worm wheel supply device 200 without error, the worm wheel 5 is supplied through the worm wheel guide 204 and installed in position. do.

FIG. 6 is a plan view of the assembly (rectangle) on the right side of FIG. 5 viewed from above along the direction of the dotted arrow. In Figure 6, the guide moving part 100 is also shown.

The guide moving unit 100 includes a pair of main bodies 102 that extend long in the y-axis direction (or longitudinal direction) and face each other at a predetermined interval, and a guide shaft installed on the upper and lower parts of each main body 102 ( 104). The main bodies 102 are spaced apart from each other in parallel. Each guide shaft 104 is installed penetratingly to cross the main body 102 in the x-axis direction (or transverse direction), and the rod 106 at the tip of each slide groove ( 206) You can enter inside. The guide shaft 104 is installed in a balanced manner at four locations in the main body 102. However, the installation location and number do not limit the scope of the present invention, and various changes are possible, such as placing a total of six units in two locations in the center or three parts at the top, middle, and bottom.

The worm wheel supply device 200 includes a base 202 mounted longitudinally between the spaces provided by the main body 102. Each slide groove 206 is formed in the base 202 to accommodate the rod 106. Since the worm wheel supply device 200 is operatively connected to the guide moving part 100 through the guide shaft 104, it can be moved in the x-axis direction of the drawing by driving the guide moving part 100. The outer surface of the base 202 may be in contact with the guide movement device 100, but this is not required. A lift housing 1 is mounted on the longitudinal center of the base 202, and a portion of the ring 10 is shown in FIG. 6.

A worm wheel guide 204 is formed in the central part of the base 202, penetrating from the upper surface to the lower surface in the height direction. Since the worm wheel (5) is supplied to the worm wheel guide (204), the lower open surface of the worm wheel guide (204) must be accurately aligned with the space where the worm wheel (5) is to be installed.

Figure 7 is a cross-sectional view cut along the aa direction of Figure 6, showing the guide moving part 100 together. The lower surface 206 of the flange of the base 202 is mounted at a position in contact with the upper surface of the vertical part 14, and the guide moving part 100 is installed on the side of the base 202 from above. That is, the guide moving part 100 and the worm wheel supply device 200 are mounted on the upper part of the lifter housing (1).

The worm wheel guide 204 viewed from the aa direction has two inner surfaces in the shape of straight lines along the height direction. Since the worm wheel guide 204 provides a movement path for the worm wheel 5, it is preferable that the distance (H) of its lower portion is substantially equal to the thickness (D) of the worm wheel (5).

Figure 8 is a cross-sectional view cut along the bb direction of Figure 7, and the guide moving part 100 is omitted. As in FIG. 7 , the lower surface 206 of the flange of the base 202 is in contact with the upper surface of the vertical portion 14. The worm wheel guide 204 viewed from the bb direction consists of a taper 204a whose inner surface gradually converges downward along the height direction, and a lower part 204b that extends continuously to the taper 204a and whose inner surface has a constant straight line. . The reason for providing the taper 204a is to smoothly insert the worm wheel 5 into the worm wheel guide 204, that is, to slide it. The distance (H') of the lower part (204b) is preferably substantially equal to the maximum outer diameter (R) of the worm wheel (5).

As such, in the present invention, the worm wheel guide 204 provides a space suitable for the thickness (D) and diameter (R) of the worm wheel (5), so when the worm wheel (5) is inserted through the upper surface of the worm wheel guide (204), the worm wheel and lifter It is possible to maintain the gap in the housing assembly within the range of 0.01 to 0.04 mm. To achieve this, the position of the worm wheel supply device 200 must first be accurately aligned.

By forming a taper on only one part of the worm wheel guide (204), free space is provided for passage of the worm wheel (5), and at the same time, the non-tapered side is brought into close contact with the worm wheel (5) to prevent shaking during insertion. It is advantageous in that it exists. Although it may be advantageous to form a taper on the surface (FIG. 8) that supports the radial direction of the worm wheel (5) in terms of satisfying the tolerance condition in the thickness direction, this is not essential, and instead, the taper is formed in the thickness direction of the worm wheel (5). It can be formed on the supporting surface. In some cases, a taper may be formed around the entire upper inner surface of the worm wheel guide 204.

The present invention uses the guide bar 300 shown in FIGS. 7 and 8 to align the position of the worm wheel supply device 200. The guide bar 300 is inserted into the worm wheel guide 204 and is thus manufactured into a shape that the worm wheel guide 204 can accommodate. Specifically, the height of the guide bar 300 is higher than that of the worm wheel guide 204. When inserted into the worm wheel guide 204, its lower end extends longer to be inserted into the lower surface of the space between the male shaft 14 of the lifter housing 1, that is, the mounting surface of the worm wheel 5, and the upper end is the worm wheel. It is in a position sufficiently exposed from the guide 204. The outer thickness of the guide bar 300 in the x-axis direction is manufactured to be substantially the same as or very slightly smaller than the distance H so that the surrounding worm wheel guide 204 comes into close contact with it, as shown in FIG. 7. The outer thickness of the guide bar 300 in the y-axis direction is manufactured to be substantially the same as the distance H' or to be very slightly smaller, so as to closely contact the lower part 204b of the worm wheel guide 204, as shown in FIG. 8. .

To align the position of the worm wheel supply device 200, insert the guide bar 300 into the worm wheel guide 204, then drive the guide moving part 100 to move the guide shaft 104 to install the worm heel supply device 200. The position where the two members come into close contact while moving left and right is determined as the worm wheel supply position, and the position of the guide shaft 104 is fixed at this position using a clamping mechanism. Then, the position of the whim wheel supply device 200 is also stably fixed. When this fixing operation is completed, the guide bar 300 retreats.

Next, with reference to FIG. 9, the mounting process of the worm wheel 5 will be described step by step based on the structure of the present invention described above.

First, the worm wheel supply device 200 is mounted on the lifter housing 1, and the guide bar 300 is inserted into the worm wheel guide 204 (S10).

Next, the guide moving unit 100 is driven to move the worm wheel supply device 200 left and right and the worm wheel supply position is determined (S12).

Next, the guide shaft 104 is clamped to fix the position of the worm wheel supply device 200 (S14).

Next, the guide bar 300 is retracted (S16).

Next, the worm wheel (5) is injected into the worm wheel supply device (200) (S18). This operation is preferably performed by the arm of the robot.

Next, the worm wheel (5) is mounted on the mounting surface of the lifter housing (1) by sliding along the taper of the worm wheel guide (104) (S20). FIGS. 10(a) and 10(b) are views corresponding to FIGS. 7 and 8, respectively, and show the intermediate position (m) and final position (f) of the worm wheel 5 during installation.

Finally, reinsert the guide bar 300 to check whether the worm wheel 5 is seated (S22). During this process, the effect of firmly pressing the worm wheel (5) to its mounting surface can be expected.

Above, preferred embodiments of the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to the embodiments and various modifications are possible.

Claims (7)

A worm wheel alignment and supply system for mounting a worm wheel to a lifter housing of an automobile. The system includes a guide moving part and a worm wheel supply device that moves left and right by driving the guide moving part, and the worm wheel supply device is supplied with a worm wheel for installation. A worm wheel alignment and supply system comprising a guide bar that is inserted into the worm wheel guide to determine a fixed position of the worm wheel supply device. According to clause 1,
The first side of the worm wheel guide is sized to accommodate the thickness of the worm wheel, and the remaining second side is sized to accommodate the outer diameter of the worm wheel extending in a direction perpendicular to the thickness of the worm wheel. According to clause 2,
A worm wheel alignment and supply system in which a taper is formed on the upper part of the second side that is inclined toward the center as it goes downward. According to clause 2,
The first side of the guide bar is the same size or slightly smaller than the first side of the worm wheel guide, the second side is the same size or slightly smaller than the second side of the worm wheel guide, and the height of the guide bar is the same as that of the worm wheel guide. A worm wheel alignment and supply system that is greater than the height of and whose lower end is adjacent to or in contact with the mounting surface on which the worm wheel of the ritter housing is mounted. According to clause 2,
A worm wheel alignment and supply system in which the guide moving part includes a guide shaft whose tip rod is coupled to the body of the worm wheel supply device, and the guide shaft operates by driving the guide moving part. A method of mounting a worm wheel to a lifter housing of an automobile, comprising:
Mounting a worm wheel supply device on the lifter housing and inserting a guide bar into the worm wheel guide of the worm wheel supply device;
Moving the worm wheel supply device to the left and right to fix the worm wheel supply position at a position where the worm wheel guide is in close contact with the guide bar;
Retracting the guide bar and separating it from the worm wheel guide; and
A worm wheel mounting method comprising the step of pushing the worm wheel into the worm wheel guide and mounting it between the spaces of the vertical portion of the lifter housing. According to clause 6,
The step of moving the worm wheel supply device is a step of moving the worm wheel supply device left and right by operating a guide shaft connected to the worm wheel supply device.