JPH04119305U - Tappet - Google Patents

Abstract

(57) [Summary] [Purpose] To improve the structure of the tappet body to make it easier to process, thereby reducing costs. [Structure] The tappet is formed by bonding a ceramic plate 2 to the bottom surface of a metal tappet body 1. The tappet main body 1 is formed by being divided into at least an upper half 1a and a lower half 1b, and the upper half 1a and the lower half 1b are joined via a brazing material 5.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention relates to a tappet used in automobile engines and the like.

0002

[Conventional technology]

In recent years, efforts have been made to improve the wear resistance of tappets in response to higher engine output, etc. For example, there is a technology to braze and join a ceramic plate to the bottom of a metal tappet body. This is disclosed in Japanese Patent Application Laid-Open No. 2-55809. The tappet body of this Japanese Patent Application Publication No. 2-55809 is JIS SNCM630 and similar. It is integrally molded from a metal material such as SKC24, and a ceramic plate is brazed to it. The metal material hardens under the heating conditions.

0003

[Problem that the idea aims to solve]

However, the JIS SNCM630, SKC24, etc. that can be applied to the conventional technology Metal materials have the disadvantage of poor workability. Therefore, if the prior art described above is implemented as is, If so, the processing cost of the tappet body would be high, which combined with the high price of the metal material itself. This makes the tappet very expensive. Tappets that require particularly deep hole drilling This tendency is strong in the case of

0004 Therefore, the purpose of this invention is to improve the structure of the tappet body to make it easier to process, thereby reducing costs. The aim is to reduce the

[0005]

[Means to solve the problem]

In order to achieve the above object, the present invention provides at least an upper half of the tappet body. It is formed by dividing into a lower half, and the upper half and lower half are joined via a brazing material. This provides a tappet that is

[0006]

[Effect] The tappet body is divided into an upper half and a lower half, each of which is processed by forging or cutting separately. Ta The shape of the pet body is usually a cylinder with a bottom or an upside-down mushroom shape, and is divided into at least two parts, top and bottom. By doing this, it can be divided into simple shapes that are easy to process. Therefore, the processability is poor. Even thin metal materials can be easily processed. The upper half and lower half thus formed are joined by brazing via a brazing material. Brazing The range of metal materials that can be joined is wider than that of welding, so the upper and lower halves The material used can be selected from among many metal materials. Therefore, wear resistance etc. You can select the most economical metal material that satisfies the required mechanical properties, so there is no waste. There is no.

[0007]

[Example 1] Fig. 1 is an exploded perspective view showing the tappet of Example 1 in half section, and Fig. 2 shows the tappet. FIG. As shown in Figures 1 and 2, the tappet is a metal tappet book. It is composed of a body 1 and a ceramic plate 2 bonded to the bottom surface of the tappet body 1.

[0008] The tappet main body 1 includes an upper half portion 1a having a cylindrical shape with a bottom, and a lower half portion 1b having a substantially truncated conical shape. It has an upside-down mushroom shape. In the center of the inner surface of the bottom wall 3 of the upper half 1a, there is a plate. A hemispherical recess 4 is formed to receive the lower end of the bush rod.

[0009] Does the upper half 1a only slide up and down in the guide hole of the cylinder block? Therefore, the required level of wear resistance is low. Therefore, it is important to use metal materials that are inexpensive and have good workability. That's fine. For example, JIS SNCM616 and JIS SNC815. and , if such metal materials lack sliding properties, wear resistance, or rigidity, Hardening treatments such as carburizing, induction hardening, and electron beam hardening may also be performed.

0010 On the other hand, the lower half 1b absorbs the impact caused by sliding with the cam and causes the ceramic plate 2 to break. Since it is necessary to prevent this, it must be of high strength. Moreover, ceramic plate It is desirable for the material to harden under the heating conditions used when brazing 2. For example, JIS S NCM630 is preferred.

[0011] The upper half part 1a and the lower half part 1b are brazed together using a brazing material 5. It is desirable that the brazing material 5 used does not contain at least phosphorus. Iron in steel material Because phosphorus in the filling material may form intermetallic compounds and significantly reduce bonding strength. It is. In addition, silicon, aluminum, iron, yttrium, etc. are added to the brazing filler metal 5 during the manufacturing process. However, it is preferable to suppress these impurities to 0.1% by weight or less. In addition, when using silver solder containing copper as the brazing filler metal 5, it is necessary to increase the copper content. This is preferable because the brazing strength can be improved. This is because steel and copper react well. Furthermore, the brazing filler metal contains elements such as zinc and cadmium that are not suitable for furnace brazing. It is preferable not to include it. When brazing the lower half 1b and the ceramic plate 2, which will be described later, This is because there is a risk of being adversely affected by non-oxidizing atmospheres such as , vacuum, and argon.

0012 The ceramic plate 2 bonded to the bottom surface of the tappet body 1 has good sliding properties with the cam and Anything that can be used to improve wear resistance and wear resistance and that can achieve these purposes. But that's fine. For example, atmospheric pressure silicon nitride is suitable.

[0013] This ceramic plate 2 and the lower half portion 1b are brazed together using a brazing material 6. wax The material 6 has the same composition as the brazing material 5 used for brazing the upper half 1a and the lower half 1b. It may have a different composition, or it may have a completely different composition.

[0014] Samples A to I as shown below were prepared based on the tappet of Example 1 as described above. The strength of the joint portion was measured as shown in FIG. In addition, in order to compare with the present invention, Samples J and K were prepared and similar strength measurements were conducted.

[0015] The dimensions of each sample A to J are: total length of tappet 50 mm, maximum diameter of lower half 1b 35 mm, The same height is 13 mm, the outer diameter of the upper half 1a is 21 mm, the same inner diameter is 15 mm, and the diameter of the ceramic plate 2. 35mm, and the same thickness is 2mm.

The ceramic plates 2 of each sample A to J are made by mixing 90% by weight of silicon nitride with a Y ₂ O ₃ -Al ₂ O ₃ based sintering aid, adding a molding binder, and molding it into a disk shape by mold pressing. After firing, both sides were polished. The upper half part 1a and the lower half part 1b were created by cutting the metal materials shown in Table 1. For samples A to E and G to I, the upper half 1a and the lower half 1b were brazed with the brazing filler metal shown in Table 1, and then the lower half 1b and the ceramic plate 2 were brazed with the brazing filler metal shown in Table 1. Further, for samples F and K, the upper half 1a and the lower half 1b were brazed, and the lower half 1b and the ceramic plate 2 were brazed at the same time. In addition, each brazing temperature is as shown in Table 1. Further, for sample J, after welding the upper half 1a and the lower half 1b by electron beam welding, the lower half 1b and the ceramic plate 2 were brazed with the brazing filler metal shown in Table 1 at a temperature.

[0017] To measure the bond strength of each sample A to K, fix each sample A to K horizontally as shown in Figure 3. , a load of up to 6,000 kg is applied to the lower half 1b and the ceramic plate 2 at a speed of 0.5 mm/min. Added W. The results are shown in Table 1.

[0018] From Table 1, the following things were confirmed. From the results of samples D and J, if the upper half 1a and lower half 1b are joined by welding, J ISSNCM447 cannot be used, but upper half 1a and lower half 1b can be connected by brazing. In this case, JIS SNCM447 can be used satisfactorily. Sample I broke from the brazed surfaces of upper half 1a and lower half 1b under a load of 3,500 kg. (However, the load capacity of 3,500 kg is sufficient for practical use.) The bonding strength gradually increases from F to sample E to samples A to D. Therefore, silver filters containing copper Increasing the copper content increases the bonding strength. Sample K contains 5% by weight of phosphorus in the brazing filler metal 5 of the upper half 1a and lower half 1b. However, it broke from the brazed surfaces of the upper half 1a and lower half 1b under a load of 500 kg. . Therefore, when the brazing filler metal 5 contains phosphorus, the brazing strength decreases.

[0019]

[Example 2] FIG. 4 is a longitudinal sectional view of a tappet showing a second embodiment. This tappet's tappet book The body 1 has an upper half 1a formed into a pipe shape, and the upper half 1a projects from the upper surface of the lower half 1b. Tightly fit into the provided circular convex portion 7 and braze with brazing filler metal 5, and then attach the push rod. A hemispherical concave portion 4 for receiving the lower end of the dome is provided in the circular convex portion 7 of the lower half portion 1b. . By making the upper half 1a into a pipe shape in this way, commercially available pipe material can be used. It is possible to save processing costs by By brazing with tight fit, the joint strength of the brazed part increases, and the upper half There are advantages such as the ability to reduce the thickness of the portion 1a.

[0020] Samples L to R as shown below were created based on the tappet of Example 2 as described above. The strength of the bonded portion was measured using the same method as described above. In addition, for comparison with the present invention, Sample S was prepared and its strength was measured.

[0021] The dimensions of each sample L to S are: total length of tappet 50 mm, maximum diameter of lower half 1b 35 mm, The height to the circular convex part 7 of the lower half part 1b is 13 mm, the height of the circular convex part 7 is 5 mm, the upper half part 1a has an outer diameter of 21 mm, an inner diameter of 15 mm, and a ceramic plate 2 has a diameter of 35 mm and a thickness of 2 mm. be.

[0022] The ceramic plates 2 of each sample L to S are the same as the sample A and the like. The upper half 1a is made of metal materials as shown in Table 2, and tested using JIS S40C. Commercially available pipes were used for samples Q and R, and round bars were cut for other samples. It was created by In addition, for the upper half 1a of samples P, Q, and S, after completion, the upper half 1 The outer periphery of a was induction hardened to a depth of 0.5 mm. The lower half 1b of each sample was cut using JIS SNCM630. For samples L, N, and O, after brazing the upper half 1a and lower half 1b with the brazing filler metal shown in Table 2, The lower half 1b and the ceramic plate 2 were brazed with the brazing filler metal shown in Table 2. Also, samples M, P , Q, and R are the brazing of the upper half 1a and the lower half 1b, and the brazing of the lower half 1b and the ceramic plate 2. Brazing was done at the same time. In addition, each brazing temperature is as shown in Table 2. In addition, for sample S, after welding the upper half 1a and the lower half 1b by electron beam welding, the lower half The portion 1b and the ceramic plate 2 were brazed to the brazing material shown in Table 2 at the temperature.

[0023] To measure the bonding strength of each sample L to S, fix each sample L to S horizontally as shown in Figure 3. , a load of up to 4,000 kg is applied to the lower half 1b and the ceramic plate 2 at a speed of 0.5 mm/min. Added W. The results are shown in Table 2.

[0024] From the results of samples P and S, J Although ISS50C cannot be used, upper half 1a and lower half 1b were joined by brazing. It was confirmed that JIS S50C can be used satisfactorily in some cases.

[0025]

[Effect of the idea]

As is clear from the above explanation, the present invention has the following advantages: First, the tappet body is separated into upper and lower halves. Since it is divided into parts, each part has a simple shape that is easy to process. Therefore, gold has poor workability. Even metallic materials can be easily processed. Second, the tappet body is divided into an upper half and a lower half. Therefore, even if the price is high for the lower half, which requires high rigidity and wear resistance, it does not meet those requirements. Using metal materials that meet the requirements, the upper half, which has low requirements such as wear resistance, can be processed at low cost. Select the most suitable metal material depending on the purpose, such as using a metal material with good properties. can save material costs. Thirdly, the upper and lower halves are connected using a brazing material. Since the welding method uses metals that are not suitable for welding, it is possible to firmly join them. This has the effect of further expanding the range of usable materials.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view showing a tappet of Example 1 in half section.

FIG. 2 is a longitudinal sectional view of the tappet of Example 1.

FIG. 3 is a cross-sectional view showing a bonding strength measurement test.

FIG. 4 is a longitudinal cross-sectional view of the tappet of Example 2.

[Explanation of symbols]

1... Tappet body 1a...upper half 1b...lower half 2...Ceramic plate 5...Brazing metal

[Table 1]

[Table 2]

Claims (1)

[Scope of utility model registration request] 1. A tappet in which a ceramic plate is bonded to the bottom surface of a metal tappet body, wherein the tappet body is divided into at least an upper half and a lower half, and the upper half and the lower A tappet characterized by having halves joined through a brazing material.