JPS59301B2 - Manufacturing method of combustion chamber insert for diesel engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a compression chamber insert for a diesel engine (hereinafter referred to as an insert) having a nozzle that is a modified nail hole.

Inserts fitted into the cylinder heads of diesel engines are exposed to high temperatures due to combustion gas, so they require heat resistance and high dimensional accuracy. Traditionally, inserts have been manufactured by investment casting or cutting from round bar materials. Manufactured by processing.

The investment casting method has made remarkable progress in recent years, mainly for gas turbine parts such as jet engines, and it has become possible to achieve high dimensional accuracy as well as complex and sophisticated control of grain size, resulting in excellent heat-resistant cast parts. It is now possible to

However, the process is complicated, the molding takes a long time, and the manufacturing cost is very high, so it cannot be said to be suitable as a method for manufacturing inserts.

- Inserts that require high strength and heat resistance must be made of heat-resistant steel, and heat-resistant steel generally has poor machinability, and machining from round bar material has an extremely low material yield. This method cannot be said to be suitable from the viewpoint of either material cost or processing cost.

In particular, when attempting to manufacture an insert having a nozzle formed of an irregularly shaped nail hole by machining, machining the nozzle is extremely difficult.

That is, in machining, the drill usually has to rotate, making it difficult to drill holes other than circular.

For this reason, machining is inappropriate for drilling holes of irregular shapes other than circular shapes (square, rectangular, oval, semicircular), especially for drilling so-called irregular nail holes that are inclined with respect to the surface of the workpiece.

In addition, it is possible to machine irregularly shaped holes using a milling machine by controlling the feed in three directions of the table, but if the workpiece is a heat-resistant material or a highly hard material, the life of the cutting tool is short and it takes a long time. However, it has disadvantages such as considerable cost, and is not suitable for mass-produced products such as inserts.

In addition, when machining difficult-to-cut materials, tools inevitably wear out during machining, so maintenance and replenishment of tools has a large impact on costs, and in terms of dimensional accuracy, the radius of the tool gradually decreases as machining progresses. Therefore, it is necessary to correct the position of the main shaft accordingly, and although it is possible to incorporate them into the device, there are disadvantages such as the device becoming expensive and the cost increasing, so it cannot be said to be suitable.

As a method of manufacturing an insert having a nozzle consisting of an irregularly shaped nail hole, a method has also been proposed in which the insert material is divided and the divided insert materials are joined after the cutting of the orifice, which is an irregularly shaped nail hole, is completed (Japanese Patent Application Laid-Open No. 138207/1982). However, since the upper and lower parts are different, cutting, processing, welding finishing, etc. are required, which naturally requires a wide variety of processes, and the material yield and
There are many problems in terms of cost, and it cannot be said to be suitable.

In order to eliminate such inconveniences, the present inventors first inserted a disc-shaped or cylindrical heat-resistant steel material with a carbon content of 0.06% or less into a goo, and then punched and counter-punched it into a cold or warm state. A manufacturing method for inserts in which the inserts are compressed between them to form a substantially concave cross-sectional shape, and then a hole is punched at the bottom (Japanese Patent Application No. 54-5316)
1) was proposed.

Since this manufacturing method involves cold or warm forging of heat-resistant steel, it is suitable for manufacturing the insert material before drilling the nozzle in terms of dimensional accuracy, productivity, reliability, etc.

However, in this manufacturing method, a conventional method is used for drilling holes in the insert material, and therefore, the drilling process requires time and labor.

As a result of intensive research to improve the problems of the above-mentioned invention, the inventor of the present invention has discovered that when molding the insert material, a deformed diagonal recess having a shape similar to the nozzle is simultaneously molded at the upper end or upper and lower ends of the part corresponding to the nozzle. As a result, a method for manufacturing a low-cost insert that reduces the number of drilling parts and facilitates drilling has been completed, leading to the present invention.

That is, the present invention includes a first step of inserting a cylindrical material made of heat-resistant steel into a goo and cold compressing it with a punch and a counter punch to form a molded object having a substantially concave cross section. The molded body is inserted into the gou with the concave portion facing downward in a state where at least a portion of the bottom wall is discharging from the top surface of the gou, and a counter punch having a convex portion that faces the concave portion and a nozzle formed of an oddly shaped nail hole are inserted into the gou. The molded body is punched with an upper punch having a small protrusion on the front end surface having a shape similar to the shape of the opening of the irregularly shaped nail hole and having a surface perpendicular to the irregularly shaped nail hole at a position corresponding to the opening. The second stage consists of cold compression to form a recess that will become the opening of the irregularly shaped nail hole, and the third stage that processes the spout of the irregularly shaped nail hole along the recess that will become the opening and performs necessary processing on the outer periphery. A method for manufacturing a vortex-type compression chamber insert for a diesel engine having a nozzle with an irregularly shaped nail hole, and a cylindrical material made of heat-resistant steel is inserted into a goo and cold compressed with a punch and a counter punch to form a substantially concave cross-section. In the first step of molding the molded body into a shaped body, the molded body is inserted into a goo with the concave portion facing downward in a state where at least a portion of the bottom wall of the molded body is discharged from the upper surface of the die, and is brought into contact with the concave portion. a counter punch having a convex portion and a small protrusion on the front surface having a shape similar to the shape of the opening of the irregularly shaped nail hole at a position corresponding to the inner circumferential opening of the nozzle consisting of the irregularly shaped nail hole; and a front end surface. is cold compressed with a flat upper punch to form a molded body having a first concave portion on the bottom surface of the concave portion, which is the opening portion of the irregularly shaped nail hole, and then placed at a position corresponding to the opening of the nozzle formed by the irregularly shaped nail hole. The molded body is cold compressed using an upper punch having a small protrusion on the front end surface having a shape similar to that of the opening of the irregularly shaped nail hole and a surface perpendicular to the irregularly shaped nail hole. A second step of forming a recess that will become an opening, and a third step of machining a spout of the irregular nail hole along the first and second recesses that will become an opening and performing necessary processing on the outer periphery. A method of manufacturing a vortex compression chamber insert for a diesel engine having a hole orifice is provided.

The present invention will be explained below with reference to the drawings.

Figures 1 and 2 are cross-sectional views of insert A manufactured according to the present invention. Insert A is a disk with a generally concave cross section, has an annular projection 5 on the outer edge of the bottom, and has an inclination angle of 15° to 75°. An irregularly shaped nail hole 10 is opened from the upper surface 6 to the lower surface 7 of the bottom.

Fig. 1 I~■, Fig. 2 and Fig. 3 show this insert 1-
The manufacturing process of A is shown.

FIG. 1I shows a substantially cylindrical heat-resistant steel cable 1 formed by any method such as cutting a round bar, and this process uses this as a starting material.

1. A substantially cylindrical heat-resistant steel cable 1 shown in FIG. 1 is inserted into a die 13 made of cemented carbide, and a punch 14 and a counter punch 15 made of cemented carbide are set above and below, as shown in FIG. 2, for example. After that, the substantially cylindrical heat-resistant steel cable 1 is pressed by a cold or warm forging method using a punch 14 to form a member 2 having a truncated cone-shaped recess 3.

Next, the punch 14 is raised and the counter punch 15 is
The member 2 is pushed out from the die 13 at.

Then, as shown in FIG. 3, for example, the member 2 is turned upside down and inserted into another die 16 made of cemented carbide, and after setting the punch 17 and counter punch 18 made of cemented carbide above and below, The member 2 is formed with a punch 17 using a cold or warm forging method.
is pressed to form a member 4 having an annular projection 5 on the outer edge of the bottom (Fig. 1 ■).

After that, raise the punch 17 and counter punch 18.
The member 4 is pushed out from the die 16.

Furthermore, as shown in FIG. 4, for example, the member 4 is mounted on a molding machine equipped with a die 19 and a counter punch 22 having the same shape as the die 16 and counter punch 18 shown in FIG. Triangular shaped nail hole 1 with irregularly shaped end surface
A punch 2 having a protrusion 21 having an oval shape that matches 0
The member 4 is press-worked by cold or warm forging using 0 to form an insert member 8 having a deformed diagonal opening 9 at the bottom (FIG. 1).

After that, raise the punch 20 and counter punch 22.
The insert member 8 is pushed out from the die 19.

Next, the insert member 8 shown in FIG. be done.

This drilling process is performed, for example, as shown in FIG. 6, after fixing the insert member 8 with a workpiece holder 29 so that the bottom q of the irregularly shaped oblique opening 9 is horizontal, a cutting tool 2 such as a drill is used.
At step 8, an irregularly shaped nail hole 10 is bored from the upper surface 6 to the lower surface of the insert member 8.

Drilling methods include cutting, electrical discharge machining, electrolytic machining,
Punching with a punch or the like can be employed, and in the present invention, the irregularly shaped nail hole 10 is obtained by using these methods alone or in combination.

In this example, after the member 4 shown in FIG. 1 is press-molded,
Although the insert member 8 shown in Fig. 1 (■) was press-molded, the first
The insert member 8 can also be directly press-molded from the member 2 shown in FIG.

Furthermore, the present invention not only provides the irregularly shaped oblique opening 9 from the upper surface 6 of the bottom as in the above embodiment, but also provides an irregularly shaped inclined opening 11 facing from the lower surface 7 of the bottom as shown in FIG. It is also possible to make the hole punching portion a as small as 0.5 mm, thereby making the hole drilling even easier.

The insert member 12 formed by the water droplet is subjected to a drilling process using a cutting tool 28 such as a drill in the same manner as the method shown in the sixth figure to form an insert t-A.

In addition, as a drilling method, after fixing the workpiece to the workpiece holder 29- as shown in FIG. 7, for example, a plurality of temporary odd-shaped nail holes 30 (in the figure, three
There is a method of drilling a nail hole 10, and then forming it into a predetermined irregularly shaped nail hole 10 by electrolytic machining.

According to this method, since the cutting tool 28 such as a drill is used to make a temporary irregularly shaped nail hole 30, the irregularly shaped nail hole 10
It is easier to carry out than directly drilling a hole, and since the temporary irregularly shaped nail hole 30 is used for electrolytic machining, the electrode for electrolysis is better aligned than with general electrolytic machining, and the temporary The irregularly shaped nail hole 30 works as a guide, reducing finishing time.
In addition, finishing processing is difficult with machining such as a drill, and irregularly shaped nail holes 16 having a special shape as shown in Figure 10, for example.
The dimensional accuracy is supplemented by electrolytic processing, making it possible to obtain inserts with high dimensional accuracy.

In this embodiment, the end face shape of the irregularly shaped nail hole 10 is approximately rectangular as shown in FIG. One side of the hole on the center side is arcuate and the two outer corners are rounded, and the four sides of a substantially square hole are arcuate as shown in Figure 10 H. Figure 10■ It is also possible to use a substantially rectangular hole with four sides shaped like an arc, as shown in FIG.

Furthermore, the shape of the insert is not limited to those shown in FIG. 1 V and
Insert B1 with the annular protrusion 5 removed from the same Insert C with the protrusion 29 in the center as shown in Figure 11, or Insert 1 with the recess 3 of insert B removed as shown in Figure 11C
-D etc. may also be used.

Note that the heat-resistant steel used in the above embodiment has a carbon content of 0.
0.06% or less, preferably 0.04%. % or less, containing iron-based super heat-resistant alloys, and vacuum melting materials and electroslab remelting materials are particularly suitable because they have good workability.

Nickel-based or cobalt-based superalloys can also be used, but these are expensive and therefore impractical.

If the carbon content exceeds 0.06%, the workability deteriorates, as is clear from the graph showing the relationship between deformation resistance and upsetting rate shown in Figure 12, and it is not recommended as a heat-resistant steel material for this type of product. is impractical.

However, in the present invention, the amount of profile material 9 and further 11 is provided in the part corresponding to the nozzle during press molding of the insert member, so the actual cutting part is small and the cutting tool is used for ordinary drilling with respect to the amount of profile material 9. Similarly, the work can be done vertically, eliminating processing problems and making it possible to use materials that were previously considered unsuitable.

However, in general, the lower the carbon content of heat-resistant steel, the better the oxidation resistance and corrosion resistance. Therefore, from the viewpoint of workability and quality, the carbon content is preferably 0.06% or less, particularly preferably 0.04%.
It is preferable to use the following heat-resistant steels:

FIG. 12 shows that the lower the carbon content, the better the workability.

Furthermore, the present invention will be explained in detail with reference to Examples.

Example First, C0,045%, Cr23'! 6.Mn0.4%
, Si0.5%, Po03%, 80.03%, and the remainder substantially Fe (HRB8
9.5) Insert member 12 shown in FIG. 5 using the material
Forged and formed.

Next, as shown in FIG. 7, after fixing the insert member 12 via the work holder 29 so that the bottom 9 of the profiled material 9 is horizontal, cut the insert member 8 from the top surface 6 with a cutting tool 28 such as a drill. The long axis e of the end surface is (12
, 8±0.15) mm, and the minor axis c and d are (5,75±0.
An irregularly shaped nail hole 10 having an oval shape of 15) mm was provided.

Here, FIG. 13 is a cross-sectional view of the insert A, FIG. 14 is a cross-sectional view of the irregularly shaped nail hole 10 taken along the line II in FIG. 13, and FIG. 15 is a cross-sectional view taken along the line ■-■ in FIG. The shape of the irregularly shaped nail hole 10 is shown in cross section.

Instead of the heat-resistant steel used in this example, SUS 310 series austenitic stainless steel (C0.06% or less, Ni
19.00-22.00% Cr24. OO~26.0
0%), 5US309 series austenitic stainless steel (
C0, 06 section and below, Ni12. OO~15.00, C
r 22.00-24.00%), SUSXM7 series austenitic stainless steel (C0.06% or less, Ni8.5
0-10.50%, Cr17, o o ~19. Oo%
), 5US405 series ferrite stainless steel (C0,0
6 or less, Cr 11.50-14.5 o%), S
US 430 series ferrite stainless steel (C0,064
Hereinafter, Cr16.00 to 18.00), low carbon alloy steel with a composition close to 5UH31 (C0,06 or less, Ni13
．． OO~15.00%, Cr 14.00~16.00
%), low carbon alloy steel (C0
, 06 or below, Nil 9.00-22.00%, C
r 24.00-26.00), low carbon alloy steel with a composition close to 5UH446 (CO, 06% or less, Cr 23.0%).
00 to 27.00), low carbon alloy steel with a composition close to 5UH3 (Co, O6% or less, Cr 10.00 to 12.0)
0%, M.

0.70-1. Substantially similar results were obtained when using 0%).

Next, Table 1 shows the results of a comparison between the insert A obtained in this example and the insert A obtained by electric discharge machining and a milling ball end mill.

A comparative example is one in which a spout is provided in the member 4 shown in Fig. 1 (■),
The cutting distance was 21 dragons.

The distance of the punched hole part a of the insert member 12 in this example was 4.2 mm, which was about % of the above-mentioned cutting distance.

For this reason, a carbide ball end mill had to be used for machining in the comparative example, but in this example)
During machining, holes could be easily drilled using a regular-shaped carbide end mill.

As described above, in the present invention, the irregularly shaped slanted top is provided at the upper and lower ends or one end of the part corresponding to the nozzle by press molding before drilling, so that a hole-drilling tool such as a drill can be used at the bottom of the irregularly shaped slanted part as in general drilling. It hits vertically, making it possible to accurately and easily form irregularly shaped nail holes.

Further, since the hole to be drilled is short and has good tool contact as described above, the hole can be easily drilled with a normal-shaped end mill, and inserts can be mass-produced at low cost.

[Brief explanation of drawings]

FIG. 1 is a process diagram in an embodiment of the present invention, FIGS. 2 to 5 are cross-sectional views showing the state of press working in an embodiment of the present invention, and FIGS. 6 and 7 are An explanatory diagram showing the state of drilling in an embodiment of the present invention, Fig. 8 is a sectional view of an insert obtained by an embodiment of the present invention, and Fig. 9 is a sectional view of an insert obtained by an embodiment of the present invention. Fig. 10 is a plan view of the recess of the insert material, Fig. 10 is an end view of the irregularly shaped nail hole, Fig. 11 is a sectional view showing a modified example of the insert, Fig. 12 is a graph showing the relationship between deformation resistance and upsetting rate, Fig. 13 14 is a sectional view of the insert, FIG. 14 is a sectional view taken along line I-4 of the irregularly shaped nail hole in FIG. 13, and FIG. 15 is a sectional view taken along line U-n. 1: heat-resistant steel material, 2, 4: member, 3: concave, 5: annular projection, 6: upper surface, 7: lower surface, 8, 12: insert member,
9, 11: Unusual oblique upward, 10: Hole, 13.16, 19, 2
3: Die, 14, 17, 20° 24: Punch, 15, 1
B, 22, 26: counter punch, 29: work holder, 28 nitrile, A, B, C, D: insert.

Claims (1)

[Scope of Claims] 1. A first step of inserting a cylindrical material made of heat-resistant steel into a goo and cold compressing it with a punch and a counter punch to form a molded product having a substantially concave cross-section; The molded body is inserted into the gou with the concave portion thereof facing downward in a state where at least a portion of the bottom wall of the gou is discharged from the top surface of the gou, and a counter punch having a convex portion that faces the concave portion and a nozzle formed of an irregularly shaped nail hole are provided. and an upper punch having a small protrusion on its front end face having a shape similar to the shape of the opening of the irregularly shaped nail hole and having a surface perpendicular to the irregularly shaped nail hole at a position corresponding to the opening of the irregularly shaped nail hole. The second stage is to cold compress the material to form a recess that will become the opening of the irregularly shaped nail hole, and the third stage is to process the spout of the irregularly shaped nail hole along the recess that will be the opening and perform necessary processing on the outer periphery. A method of manufacturing a vortex-type compassion chamber insert for a diesel engine having a nozzle having an irregularly shaped nail hole. 2. A first step in which a cylindrical material made of heat-resistant steel is inserted into a goo and cold-compressed with a punch and a counter punch to form a molded body having a generally concave cross-section; at least one of the bottom walls of the molded body is The molded body is inserted into the gou with the concave part facing downward in a state where the part is discharged from the top surface of the gou, and the molded body has a convex part that opposes the concave part and corresponds to the inner circumferential opening of the nozzle which is an irregularly shaped nail hole. a counter punch having a small protrusion on the front surface having a shape similar to the shape of the opening of the irregularly shaped nail hole at a position where the nail hole is opened;
The molded body is cold-pressed with an upper punch having a flat front end surface to form a molded body having a first recess on the bottom surface of the recess which becomes the opening of the irregularly shaped nail hole, and then the molded body is formed at a position corresponding to the opening of the nozzle formed by the irregularly shaped nail hole. Then, the molded body is cold-compressed with an upper punch having a small protrusion on the front end surface that has a shape similar to the shape of the opening of the irregularly shaped nail hole and has a surface perpendicular to the irregularly shaped nail hole, thereby forming an irregularly shaped nail. The second step is to form a recess that will become the opening of the hole, and the third step is to process the nozzle of the odd-shaped nail hole along the first and second recesses that will become the opening, and to perform necessary processing on the outer periphery. A method of manufacturing a vortex-type compassion chamber insert for a diesel engine having a nozzle with an irregularly shaped nail hole.