JPH0835407A - Push rod and its manufacture - Google Patents

Abstract

PURPOSE:To eliminate a possibility that a pipe is buckled by an axial load by welding an end fitting to the pipe through a plate-like adapter on which a center hole for the end fitting is bored in a push rod provided with end fittings on both ends of the pipe. CONSTITUTION:In a push rod wherein an end fitting 2 is attached on the tip surface 1-1 of a normal pipe 1 through a plate-like adapter 3, a center hole 3-1 into which a protrusion 2-1 of the end fitting 2 is to be fitted is bored on the plate-like adapter 3, and one side surface of this adapter 3 is welded to the pipe 1, and the protrusion 2-1 of the end fitting 2 is fitted into and welded to the center hole 3-1 from the other side surface. By such a push rod, there is no possibility that the pipe 1 is buckled by an axial load, and a fine vibration is not generated on the push rod itself, and a rocker arm and a tappet such as a counterpart member can be miniaturized. Accordingly, the whole mechanism can be miniaturized, and a lightweight internal combustion engine can be realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a push rod for operating an intake valve and an exhaust valve in an internal combustion engine and a method for manufacturing the push rod.

[0002]

2. Description of the Related Art As is well known, valve push rods generally have a structure in which both end portions of a pipe are welded with end fittings having a concave or convex arcuate surface in the axial direction. Target. Such push rods are connected to rocker arms and tappets through end fittings,
In order to reduce the size of the rocker arm or tappet or the weight of the product, it is preferable to reduce the size or weight of the push rod.

As means for miniaturizing the push rod, for example, miniaturization of end fittings and adoption of thin-walled pipes can be considered. However, if the diameter of the pipe itself is made small in order to miniaturize the end fitting, the axial direction of the pipe Since there is a risk that the pipe will buckle due to the load, the method of using a small-diameter pipe to miniaturize the push rod is not practical. On the other hand, in the method of using a relatively thin pipe to reduce the weight of the product, a slight vibration is generated in the push rod itself as the engine speed increases, and the small vibration propagates to the intake valve and the exhaust valve. However, there is a problem that it adversely affects the smooth rotation of the machine. Therefore, as the pipe forming the push rod, it is preferable to use a normal large-diameter pipe having both an outer diameter and a wall thickness. However, it is the actual situation that a push rod that is made smaller or lighter using an ordinary pipe has not been manufactured.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and there is no risk of the pipe buckling due to an axial load applied to the pipe, and a slight vibration occurs in the push rod itself. It is therefore an object of the present invention to propose a push rod and a manufacturing method thereof which can reduce the size of a rocker arm or tappet and the weight of an internal combustion engine.

[0005]

A push rod according to the present invention comprises an ordinary pipe, a small end fitting and an adapter. The gist of the push rod is that a bottom portion of the end fitting is provided with a central hole. Is a push rod formed by welding an end fitting to a pipe through a plate-shaped adapter, and a projection protruding in the axial direction is provided on the bottom of the end fitting, and the projection is fitted into the central hole of the plate-shaped adapter. Further, at least one side surface of the plate-shaped adapter is provided with one of a cylindrical protrusion that can be fitted inside the pipe and a cylindrical protrusion that can be fitted outside the protrusion of the end fitting. A push rod having a chrysanthemum seat formed on either or both of a surface of the plate adapter facing the pipe and a surface of the plate adapter facing the end fitting, and the plate adapter. Chrysanthemum The tip end of the opposing pipe or the bottom surface of the end fitting is formed with a pointed end and is welded to the chrysanthemum seat, and the tubular projection part fitted in the pipe of the plate adapter is a bottomed cylinder. It is characterized in that it is constituted by a body, and further, an annular groove for welding in which the tip portion of the pipe is fitted is provided on one side surface of the plate-shaped adapter, wherein the welding is seam welding, projection welding or friction. It is characterized by being welded.

In addition, as a method of manufacturing the push rod, one end of the plate-shaped adapter is pressed against the tip end surface of the pipe to seam or friction weld the pipe and the adapter,
After that, the projection of the end fitting is fitted in the central hole of the adapter to perform projection welding of the other side surface of the adapter and the end fitting. As another method, the end fitting of the end fitting is fitted in the central hole of the plate-shaped adapter. The other side of the adapter and the end fitting are projection-welded by fitting the projection, and then one side of the plate-shaped adapter is pressed against the tip end of the pipe to seam-weld or friction-weld the pipe and the adapter. It is what

[0007]

In the present invention, the reason for downsizing the end fittings is that the mating member, that is, the rocker arm or tappet can be downsized as described above, and therefore not only the mechanism can be downsized as a whole, but also the weight can be reduced. .

In the present invention, a plate adapter is used as a means for attaching the small end fitting to a normal pipe. By using this plate adapter, a normal pipe can be used, and a rocker arm or rocker arm can be used. The tappet can be made smaller and lighter.

Further, preferably, the plate-shaped adapter can be positioned simply and quickly by providing a cylindrical protrusion that can be fitted in the pipe on the surface of the plate-shaped adapter facing the pipe. Of course, since the portion of the cylindrical protrusion can be seam welded to the end of the pipe, the welding can be performed easily, quickly and accurately. On the other hand, a small end fitting can be attached to an ordinary pipe by providing a tubular projection on the end fitting mounting surface side of the plate-shaped adapter that can be fitted onto the projection of the end fitting. Furthermore, if a plate-shaped adapter provided with a cylindrical projecting portion on the side facing the pipe and on the mounting surface side of the end fitting is used, positioning of the plate-shaped adapter and welding with the pipe end can be performed simply, quickly and with high accuracy. Can be done well.

Further, the chrysanthemum seat provided on one side surface or both side surfaces of the plate-shaped adapter is formed so as to extend radially with respect to the shaft core and has a wedge-shaped cross section, which is usually a pipe or an end. It may be formed to be harder than the metal fitting, and as its means, for example, the chrysanthemum seat portion is quenched. Such a chrysanthemum seat can be similarly provided in the case of a plate-shaped adapter having a cylindrical protrusion on the surface facing the pipe, the end fitting mounting surface, or both sides.

If a chrysanthemum seat is provided on one side surface or both side surfaces of the plate-shaped adapter, for example, when the plate-shaped adapter is pressed with a slight inclination with respect to the pipe, or when the plate-shaped adapter is welded to the pipe, On the other hand, even when the end fitting is pressed with a slight inclination, the inclination is automatically corrected.

That is, for example, when welding the plate-shaped adapter to the pipe, a part of the projecting end of the chrysanthemum of the plate-shaped adapter comes into contact with the open end surface of the pipe. At that time, since the chrysanthemum of the plate-shaped adapter is harder than the pipe, the abutting pipe opening ends immediately begin to deform, but the projecting ends of the chrysanthemum are wedge-shaped and abut each other so that they are deformed. The deformation resistance rapidly increases not only in the radial direction of the opening end but also in the circumferential direction. For this reason, the initial inclination cannot be maintained, the angle of the inclination gradually decreases, and the opposite side of the projecting end of the chrysanthemum starts to contact the open end of the pipe. From this tendency, the more pressing force increases,
The deformation resistance due to the wedge shape further increases, the inclination angle decreases until the deformation resistance becomes substantially equal in the circumferential direction, and finally becomes substantially zero, and the inclination disappears.

Therefore, even if a slight deviation occurs in the set, the correction is automatically performed, so that the plate adapter and the pipe can be welded to each other in a uniform state. This is also the case when the end fitting is pressed against the plate adapter welded to the pipe with a slight inclination, and in the case of a plate adapter with a cylindrical protrusion on one side or both sides. Is also the same. The above-described effects can be further exerted by forming a pointed tip on the tip end surface of the pipe facing the chrysanthemum and the bottom surface of the end fitting so as to have a substantially triangular cross section.

Further, when the tubular protruding portion to be fitted into the pipe of the plate-shaped adapter is a bottomed tubular body, when the tubular body portion is seam welded to the pipe, the tubular body portion is pressed by the roll electrode. Deformation is prevented and seam welding can be performed more completely.

If an annular groove for welding with which the tip of the pipe is fitted is provided on one side surface of the plate adapter, not only the positioning of the plate adapter with respect to the pipe can be performed easily, but also the welding can be performed accurately. It can be carried out.

As a method of manufacturing the push rod of the present invention, a plate adapter is welded to the tip of the pipe and then an end fitting is welded to the plate adapter, or an end fitting is welded to the plate adapter. The method of welding the plate adapter to the pipe, that is, the method of welding in two steps without simultaneously welding the end fitting, the adapter, and the pipe, is because the end fitting, the adapter, and the pipe are welded at the same time. This is because the difference between the two is different, and thus metal deterioration due to poor welding or overheating is likely to occur.

The welding method in the present invention may be seam welding, projection welding or friction welding, and is appropriately selected and used according to the place or member to be welded.

[0018]

1 is a vertical sectional side view of an essential part showing an example of a push rod corresponding to claims 1 and 2 of the present invention, and FIG. 2 is a vertical sectional side view of an essential part showing an example of a push rod corresponding to claim 3 of the present invention. In the figure, (A) is an example of using a plate-shaped adapter having a cylindrical protruding portion on the pipe facing surface side, and (B) is a plate-shaped adapter having a cylindrical protruding portion on the end fitting mounting surface side. Example,
(C) shows an example using a plate-shaped adapter provided with cylindrical protrusions on both side surfaces. FIG. 3 is a view showing an example of a plate adapter of a push rod corresponding to claims 4 and 5, and FIG. 3A is a perspective view showing a plate adapter having a chrysanthemum seat on the pipe facing surface side, and FIG. Is a perspective view showing a plate-shaped adapter similarly provided with a chrysanthemum seat on the end fitting mounting surface side, and (C) is a vertical cross-sectional side view showing a plate-shaped adapter similarly provided with chrysanthemum seats on both side faces,
(D) is a vertical sectional side view showing a plate-like adapter having a chrysanthemum seat on the pipe-opposing surface side of a member having a pipe-projecting surface on the pipe-opposing surface side, and (E) is a tubular projection portion on both side surfaces 4 is a vertical sectional side view showing a plate-shaped adapter in which chrysanthemums are provided on both sides of the closed member, FIG.
Is a vertical sectional side view of an essential part showing an example of the push rod corresponding to claim 6, FIG. 5 is a vertical sectional side view of an essential part showing an example of the push rod corresponding to claim 7, and FIG. It is explanatory drawing which shows an example of the manufacturing method of a corresponding push rod, (A) is a longitudinal side view of the principal part which shows the state which is welding the plate-shaped adapter to a pipe, (B) Welds an end metal fitting to a plate-shaped adapter. FIG. 7 is an explanatory view showing an example of a manufacturing method of a push rod corresponding to claim 10, similarly to FIG. 7, in which (A) welds an end fitting to a plate-like adapter. A vertical sectional side view of a main part showing a state,
(B) is a longitudinal sectional side view of a main part showing a state in which a plate-shaped adapter having end fittings welded thereto is welded to a pipe.
Is an end fitting, and 3 is a plate adapter.

That is, FIG. 1 shows a push rod having a structure in which an end fitting 2 having a concave curved surface is attached to a tip end surface 1-1 of a normal pipe 1 via a plate adapter 3, and the plate adapter 3 is Both side surfaces are flat, and a central hole 3-1 is formed in such a size that the projection 2-1 protruding in the axial direction from the bottom of the small end fitting 2 can fit therein. 1, and the end fitting 2 is joined to the outer side surface. The plate adapter 3 and the pipe 1, and the plate adapter 3 and the end fitting 2 are joined by welding.

FIG. 2 shows an example of a push rod using a plate-shaped adapter having a cylindrical protrusion on its side surface.
Is an example using a plate-shaped adapter 3a having a cylindrical protrusion 3a-1 that can be fitted into the pipe 1 on one side surface. In this case, the outer surface of the cylindrical protrusion 3a-1 of the plate-shaped adapter 3a and the pipe The pipe 1 and the plate-shaped adapter 3a are welded to each other at a contact portion between the inner peripheral surface 1 and the inner peripheral surface thereof, and the spherical end fitting 2 is welded to the outer surface thereof.

Similarly, FIG. 2B shows a cylindrical projection 3b-having an inner diameter large enough to allow the convex curved bottom of the plate-shaped end fitting 2 having a concave curved surface to be attached to the end fitting. In the example using the plate adapter 3b having
b is welded to the opening front end surface 1-1 of the pipe 1, and the end fitting 2
Is welded to the open end surface of the cylindrical protruding portion 3b-1.

Similarly, FIG. 2 (C) shows an example using a plate-shaped adapter having cylindrical protrusions on both side surfaces. The cylindrical protrusions 3c-1 and 3c are provided on the pipe 1 side and the end fitting 2 mounting surface side, respectively. Is a push rod in which a plate-shaped adapter 3c having -2 is welded to the pipe 1 and the end fitting 2 is welded to the plate-shaped adapter 3c. In this case, the cylindrical projection 3c-1 has an outer diameter that can be fitted into the pipe 1, and an inner diameter that is large enough to fit the protrusion 2-1 of the end fitting 2.

Further, FIG. 3 shows a plate-shaped adapter having a chrysanthemum seat on one side surface or both side surfaces, and FIG. This is a plate-shaped adapter 3d having a chrysanthemum seat 3d-1 that is substantially triangular and is formed radially with respect to the axis. In the case of this adapter, the end fitting 2 is attached to the pipe 1 via the chrysanthemum seat 3d-1. The chrysanthemum 3d-1 may be formed harder than the pipe or the end fitting by means of local quenching. In this case, since the plate-shaped adapter 3d is welded to the opening tip surface 1-1 of the pipe 1 through the portion of the chrysanthemum 3d-1,
Even if the plate-shaped adapter 3d is set to be slightly inclined with respect to the pipe 1, it is welded uniformly over the entire circumference by the above-described automatic correction action, and in particular, the tip surface 1-1 of the pipe 1 will be described later with reference to FIG. ), (D), and (E), the effect becomes more effective when the tip is sharpened in a substantially triangular cross section.

Similarly, FIG. 3 (B) shows a plate-shaped adapter 3e having a chrysanthemum 3e-1 formed on the end fitting mounting surface side.
In this case, the end fitting 2 is welded to the plate adapter 3e via the chrysanthemum 3e-1. Also in this case, even if the end fitting 2 is set slightly inclined with respect to the plate-shaped adapter 3e, the end fitting 2 is uniformly welded over the entire circumference by the same automatic correction action as described above.

Similarly, in FIG. 3 (C), chrysanthemums 3f-1 and 3f- are provided on both sides of the surface facing the pipe 1 and the end fitting mounting surface.
2 shows a plate-shaped adapter 3f in which 2 is formed. In this case, the tip end surface 1-1 of the pipe 1 and the plate-shaped adapter 3f are welded via the chrysanthemum seat 3f-1, and the kikuza 3f-2 is used. The annular tip 2-2 formed on the bottom surface of the end fitting 2 and the plate adapter 3f are welded together.

Similarly, FIG. 3D shows a plate-shaped adapter 3g having a cylindrical protrusion 3g-1 which can be fitted in the pipe 1 on one side.
Is provided with a chrysanthemum seat 3g-2 on the pipe facing surface side, and the opening end face 1-1 of the pipe 1 is brought into contact with the portion of the chrysanthemum seat to weld the plate adapter 3g to the pipe 1. There is.

Similarly, in FIG. 3 (E), the cylindrical protrusions 3 are formed on both side surfaces.
The chrysanthemum 3h-3 and 3h-3 are respectively provided on the pipe facing surface side and the end fitting mounting surface side of the plate adapter 3h provided with h-1 and 3h-2.
3h-4 is provided, the open end surface 1-1 of the pipe 1 is brought into contact with the portion of the chrysanthemum 3h-3, and the plate-shaped adapter 3g.
The pipe 1 and the pipe 1 are welded to each other, and the annular tip 2-2 formed on the bottom surface of the end fitting 2 is brought into contact with the portion of the chrysanthemum 3h-4 to weld the end fitting and the plate-shaped adapter 3g.

FIG. 4 shows a bottomed cylindrical body 3i-on the side facing the pipe.
1 is a push rod using a plate-shaped adapter 3i provided with 1. In the case of this plate-shaped adapter 3i, since the tubular body has a bottom, the strength in the pipe radial direction is strong. Therefore, when the tubular body portion is seam-welded or radial projection-welded to the pipe, a roll or a rod-shaped electrode is used. Deformation is prevented by the high rigidity of the tubular body part due to the pressing force of
More complete seam welding and projection welding can be performed.

FIG. 5 shows an annular groove 3j-2 in which the tip end surface 1-1 of the pipe 1 is fitted to one side surface of an adapter having a central hole 3j-1 into which the projection 2-1 of the end fitting 2 can be fitted. It is a push rod using a plate-shaped adapter 3j formed with. In this case, the opening tip surface 1-1 of the pipe 1 and the annular groove 3j-
The plate-shaped adapter 3j and the pipe 1 are welded to each other at the contact portion of 2, so that welding burrs do not come out to the outside, and extra work such as deburring can be omitted.

FIG. 6 illustrates a method of manufacturing the push rod according to the present invention, in which a plate adapter is welded to the tip of a pipe and then the end fitting 2 is welded to the plate adapter. 2 shows a state in which the plate-shaped adapter 3a shown in FIG. 2 is seam-welded to the tip of the pipe 1, (B)
Shows the state in which the end fitting 2 is projection welded to the plate-shaped adapter 3a welded to the pipe 1. In the figure, 4 is a seam welding roll electrode, 5 is a seam weld, and 6 is a projection weld.

FIG. 7 shows a method of manufacturing the push rod according to the present invention, which is the reverse of the method shown in FIG. 6, in which the end fitting is first welded to the plate adapter and then the plate adapter is welded to the pipe. (A) shows a state where the end fitting 2 is projection welded to the plate adapter 3a, and (B) is a plate adapter 3a where the end fitting 2 is welded.
1 shows a state in which resistance welding is performed on the pipe 1 by the electrode rod 4-1.

As shown in FIG. 6 or FIG. 7, by adopting a method of welding the end fitting, the adapter and the pipe in two stages without simultaneously welding the end fitting, the adapter and the pipe as a method of manufacturing the push rod, Even if the pipes have different wall thicknesses or contact portions with different resistances, it is possible to manufacture a push rod of excellent quality, which is unlikely to cause defective welding or metal deterioration due to overheating.

[0033]

As described above, since the push rod according to the present invention is constructed by using a normal pipe and welding a small end fitting through an adapter, a load in the axial direction applied to the pipe is obtained. Therefore, there is no risk of the pipe buckling, and the push rod itself does not generate a slight vibration, and the rocker arm or the tappet, which is a mating member, can be miniaturized, and therefore the mechanism can be miniaturized as a whole. In addition to the above, there is an excellent effect that the weight of the internal combustion engine can be reduced.

Further, according to the method of the present invention, even if the wall thicknesses of the end fitting, the adapter, and the pipe are different from each other, no defective welding or metal deterioration due to overheating is caused, so that the quality is excellent. The effect is that a small and lightweight push rod can be manufactured.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of an essential part showing an example of a push rod corresponding to claims 1 and 2 of the present invention.

FIG. 2 is a vertical sectional side view of an essential part showing an example of a push rod corresponding to claim 3 in which (A) is an example using a plate-shaped adapter provided with a cylindrical protrusion on the pipe facing surface side, (B) () Shows an example using a plate-shaped adapter having a cylindrical protruding portion on the end fitting mounting surface side, and (C) shows an example using a plate-shaped adapter having a cylindrical protruding portion on both side surfaces.

FIG. 3 is a view showing an example of a plate adapter of a push rod corresponding to claims 4 and 5, and FIG. 3A is a perspective view showing a plate adapter having a chrysanthemum seat on the pipe facing surface side; )
Is a perspective view showing a plate-shaped adapter also having a chrysanthemum seat on the end fitting mounting surface side, (C) is a vertical cross-sectional side view showing a plate-shaped adapter also having chrysanthemum seats on both side faces, and (D) is a pipe facing surface. Side view of a plate adapter having a chrysanthemum seat on the pipe-opposing surface side of a member having a cylindrical protrusion on one side, (E) shows a chrysanthemum on both sides of a member having a cylindrical protrusion on both sides. It is a vertical side view which shows the plate-shaped adapter which provided the seat.

FIG. 4 is a vertical sectional side view of an essential part showing an example of a push rod corresponding to claim 6;

FIG. 5 is a vertical sectional side view of an essential part showing an example of a push rod corresponding to claim 7;

FIG. 6 is an explanatory view showing an example of a method of manufacturing the push rod according to claim 9, wherein FIG. 6A is a vertical cross-sectional side view of essential parts showing a state in which a plate adapter is welded to a pipe;
(B) is a vertical sectional side view of essential parts showing a state in which an end fitting is welded to a plate-shaped adapter.

FIG. 7 is an explanatory view showing an example of a method of manufacturing a push rod corresponding to claim 10, wherein (A) is a longitudinal cross-sectional side view of essential parts showing a state in which an end fitting is welded to a plate-like adapter;
FIG. 3B is a vertical cross-sectional side view of essential parts showing a state where the plate-shaped adapter having the end fittings welded thereto is welded to the pipe.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Pipe, 1-1 Tip surface 2 End fitting 2-1 Protrusion 2-2 Annular tip 3, 3a to 3i Plate adapter 3a-1, 3b-1, 3c-1, 3c-2, 3h-1,
3h-2 Cylindrical protrusion 3d-1, 3e-1, 3f-1, 3f-2, 3g-2
3h-3, 3h-4 Kikuza 3i-1 Bottomed tubular body 4 Seam welding roll electrode 5 Seam welding part 6 Projection welding part

Claims (10)

[Claims] 1. A push rod having end fittings at both ends of a pipe, wherein the end fittings are welded to the pipe through a plate-shaped adapter having a central hole. 2. The push rod according to claim 1, wherein a projection protruding in the axial direction is provided on a bottom portion of the end fitting, and the projection is fitted in a central hole of the plate adapter. 3. At least one side surface of the plate-shaped adapter is provided with one of a cylindrical protrusion that can be fitted inside a pipe and a cylindrical protrusion that can be fitted outside a protrusion of the end fitting. The push rod according to claim 1 or 2, which is characterized. 4. The push rod according to claim 1, wherein a chrysanthemum is formed on either or both of a surface of the plate-shaped adapter facing the pipe and a surface facing the end fitting. . 5. The push rod according to claim 4, wherein the tip end of the pipe or the bottom surface of the end fitting facing the chrysanthemum of the plate-shaped adapter is formed with a sharp tip and welded to the chrysanthemum. 6. The push rod according to claim 3, wherein the tubular protrusion that is fitted into the pipe of the plate adapter is a bottomed tubular body. 7. The push rod according to claim 1, wherein an annular groove for welding into which a tip portion of a pipe is fitted is provided on one side surface of the plate adapter. 8. The push rod according to claim 1, wherein the welding is seam welding, projection welding or friction welding. 9. The adapter is seamed or friction welded between the pipe and the adapter by press-contacting one side surface of the plate-shaped adapter to the tip end surface of the pipe, and then the protrusion of the end fitting is fitted into the central hole of the adapter. A method for manufacturing a push rod, characterized in that the other side surface and the end fitting are projection-welded. 10. A projection of an end fitting is fitted into a central hole of the plate adapter to perform projection welding on the other side surface of the adapter and the end fitting, and then one end of the plate adapter is pressure-welded to the tip end surface of the pipe. A method of manufacturing a push rod, characterized in that the pipe and the adapter are seam-welded or friction-welded.