Diesel indicator valve stem assembly installation aid and method

Abstract

Provided is a diesel indicator valve valve rod assembly installation auxiliary device and method, through optimizing the valve rod assembly installation structure, and under the positioning and guiding action of the auxiliary device, the upper end of the valve rod is deformed and turned inward to completely wrap the butterfly spring and the lower end of the valve head maximum diameter position in the valve rod large diameter section stepped hole by means of a press, the technical problem that the indicator valve valve rod assembly cannot be directly assembled is solved, the problems that the valve head is assembled into the valve rod inner hole and the length of the inner cavity is accurately controlled to ensure the stroke of the valve when the valve head, the valve rod and the butterfly spring are assembled are effectively solved, the valve rod assembly is smoothly assembled, the structure is simple, easy to operate and convenient to use, and the assembly quality and processing efficiency can be effectively ensured.

Description

Technical Field

[0001] This invention belongs to the field of diesel engine technology, specifically relating to an auxiliary device and method for installing a diesel engine indicator valve stem assembly. Background Technology

[0002] The diesel engine indicator valve assembly is a component that measures the intra-cylinder combustion pressure and plots the combustion pressure curve by connecting an indicator gauge. Currently, most diesel engine indicator valve assemblies are of the split type, with the valve stem, valve head, and spring connected by threads. This type of indicator valve is simple to assemble, but adjusting the valve's stroke requires rotating the thread. Rotating the nut causes the valve head to rotate, thus posing a risk of damaging the valve face. However, if a different type of valve is used... Figure 3 The illustrated indicator valve stem assembly structure is designed as a single unit, giving the indicator valve flexibility and allowing for precise control of the stem's inner cavity length to ensure valve stroke without readjustment. However, during indicator valve assembly, the stem assembly must be assembled first, involving sequentially inserting the butterfly spring and indicator valve head into the inner bore of the stem head, ensuring the valve head is completely enclosed within the stem. While this type of indicator valve structure is flexible and simple, the inner bore diameter of the stem head is Φ13mm, the maximum diameter of the portion of the valve head inserted into the stem is Φ14.5mm, and the outer diameter of the butterfly spring is Φ14mm, making direct assembly impossible. Therefore, to address the critical issue of precisely controlling the inner cavity length and inserting the valve head into the stem bore to guarantee valve stroke, improvements are necessary. Summary of the Invention

[0003] The technical problem solved by this invention is to provide an auxiliary device and method for installing a diesel engine indicator valve stem assembly. By optimizing the installation structure of the valve stem assembly and, with the positioning and guidance of the auxiliary device, using a press, the upper end of the valve stem is deformed and turned inward until the butterfly spring and the maximum diameter position of the lower end of the valve head are completely wrapped in the stepped hole of the large diameter section of the valve stem. This solves the technical problem that the indicator valve stem assembly cannot be directly assembled. It can effectively solve the problems of inserting the valve head into the inner hole of the valve stem and accurately controlling the length of the inner cavity to ensure the valve stroke during the assembly of the indicator valve head, valve stem, and butterfly spring. It ensures smooth assembly of the valve stem assembly, has a simple structure, is easy to operate, and is convenient to use, and can effectively guarantee assembly quality and processing efficiency.

[0004] The technical solution adopted in this invention is as follows: A diesel engine indicator valve stem assembly installation auxiliary device, including an upper mold, a guide sleeve, a lower mold, and a base. The base has a central hole for the lower half of the valve stem, which is vertically arranged with its small end facing downwards, to extend into it. The lower end of the guide sleeve is coaxially fixed to the upper end of the base. The lower mold is adapted to be installed inside the guide sleeve, and the lower end face of the lower mold contacts the upper end face of the base. The tapered section at the upper end of the valve stem and the lower half of the large diameter section are adapted to the lower mold hole at the upper end of the central hole of the lower mold. The upper mold is adapted to be inside the guide sleeve, and the upper mold hole at the lower end of the central hole of the upper mold is adapted to the large diameter section of the valve stem. The upper end of the upper mold extends out of the guide sleeve. When the punch of the press presses the upper mold downwards until the upper mold moves down to the point where its lower end face contacts the upper end face of the lower mold, the upper end of the valve stem deforms and flips inwards to completely wrap the butterfly spring and the maximum diameter position of the lower end of the valve head within the stepped hole of the large diameter section of the valve stem.

[0005] The base is a stepped column structure with an upper diameter smaller than the lower diameter. The lower inner hole of the guide sleeve is interference-fitted with the small diameter section of the upper end of the base, and the lower end face of the guide sleeve is in contact with the stepped surface of the base.

[0006] Furthermore, the inner hole of the guide sleeve is clearance-fitted with the upper and lower dies, and the lower end face of the lower die contacts the upper end face of the small diameter section of the base.

[0007] Furthermore, the gap between the inner wall of the guide sleeve and the outer circumferential walls of the upper and lower dies is 0.025mm to 0.075mm.

[0008] Furthermore, the diameter of the upper die hole is larger than the diameter of the center hole of the upper die, and the upper die hole and the center hole of the upper die are connected by a rounded transition, and the arc formed by the rounded corner presses the upper end of the valve stem.

[0009] The installation method for the diesel engine indicator valve stem assembly includes the following steps:

[0010] 1) Valve stem assembly optimization and installation: Optimize the stepped hole of the large diameter section of the valve stem so that the diameter of the stepped hole opening is larger than the maximum diameter of the valve head part installed in the valve stem, and extend the hole depth corresponding to the maximum diameter of the valve head; install the butterfly spring into the stepped hole, and make the valve head pass through the butterfly spring into the stepped hole, and the maximum diameter of the valve head is located at the opening of the stepped hole.

[0011] 2) Installation of valve stem assembly and auxiliary device: Fix the guide sleeve to the base and ensure that the guide sleeve and the base fixing structure are stable. Then install the lower mold into the guide sleeve, then install the valve stem assembly, and finally install the upper mold into the guide sleeve. It is necessary to ensure that the lower mold and the upper mold can move up and down flexibly within the guide sleeve.

[0012] 3) Pressing: Place the installed structure on the worktable below the press punch, start the press, and stop when the press punch presses against the upper die and moves down until the lower end face of the upper die is against the upper end face of the lower die. At this time, the upper end of the large end of the valve stem in the valve stem assembly is turned inward to wrap the maximum diameter position of the valve head inside it.

[0013] 4) After pressing is completed, the press punch moves up and the upper die and valve stem assembly can be removed.

[0014] Furthermore, a lower die hole is concentrically formed at the upper end of the lower die center hole. The lower die hole consists of a tapered hole connected to the center hole and a hole of equal diameter located at the opening. The diameter of the hole of equal diameter is larger than the largest part diameter of the valve stem big end.

[0015] Furthermore, an upper die hole is concentrically formed at the lower end of the center hole of the upper die, and the diameter of the upper die hole is smaller than the diameter of the equal diameter section of the lower die hole but larger than the largest part diameter of the valve stem's large end. During the process of the press punch pressing the upper die downward, the arc surface connected by the upper die hole and the center hole of the upper die presses the upper end of the valve stem.

[0016] Furthermore, the base is made of 45 steel and is heat-treated as a whole, with a hardness of 28-32 HRC; the upper mold, guide sleeve and lower mold are all made of GCr15 steel, with a hardness of 58-62 HRC.

[0017] Furthermore, the diameter of the central hole of the upper mold is smaller than the maximum diameter of the valve head and larger than the diameter of the upper end of the valve head.

[0018] Advantages of this invention compared to existing technologies:

[0019] 1. This technical solution optimizes the valve stem assembly installation structure and, with the positioning and guidance of the auxiliary device, uses a press to deform and invert the upper end of the valve stem until the butterfly spring and the maximum diameter position of the lower end of the valve head are completely wrapped in the stepped hole of the large diameter section of the valve stem. This solves the technical problem that the valve stem assembly of the indicator valve cannot be directly assembled. It can effectively solve the problems of valve head insertion into the valve stem inner hole and precise control of the inner cavity length to ensure the valve stroke when assembling the valve head, valve stem and butterfly spring of the indicator valve, ensuring the smooth assembly of the valve stem assembly;

[0020] 2. This technical solution has a simple structure, is easy to operate on-site, and is convenient to use. It reduces the processing and assembly difficulty of the valve stem assembly, effectively ensures assembly quality and processing efficiency, and provides a reference solution for the assembly technology of similar indicator valve stem assemblies. It has high application and promotion value. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the valve stem assembly and auxiliary devices after installation.

[0022] Figure 2 This is a schematic diagram of the valve stem structure of the present invention;

[0023] Figure 3 This is a schematic diagram of the valve stem assembly of the indicator valve;

[0024] Figure 4 This is a cross-sectional view of the lower mold of the present invention;

[0025] Figure 5 This is a cross-sectional view of the upper mold of the present invention. Detailed Implementation

[0026] The following will be based on embodiments of the present invention. Figure 1-5 The technical solutions in the embodiments of the present invention are clearly and completely described herein. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0027] It should be noted that, unless otherwise stated herein, the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," and "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0028] In this document, the terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0029] Auxiliary devices for installing the indicator valve stem assembly of a diesel engine, such as... Figure 3As shown, the device includes an upper mold 1, a guide sleeve 2, a lower mold 3, and a base 4. The base 4 has a central hole for the lower half of a valve stem 5, which is vertically positioned with its smaller end facing downwards, to extend into it. The lower end of the guide sleeve 2 is coaxially fixed to the upper end of the base 4. The lower mold 3 is fitted into the guide sleeve 2, and its lower end face contacts the upper end face of the base 4. The tapered section at the upper end of the valve stem 5 and the lower half of its larger diameter section are connected to the lower mold hole 3 at the upper end of the central hole of the lower mold 3. 1. Adaptation: The upper mold 1 is adapted to the guide sleeve 2, and the upper mold hole 1-1 at the lower end of the center hole of the upper mold 1 is adapted to the large diameter section of the valve stem 5. The upper end of the upper mold 1 extends out of the guide sleeve 2. When the punch of the press presses the upper mold 1 downward until the upper mold 1 moves down to contact the upper end face of the lower mold 3, the upper end of the valve stem 5 is deformed and turned inward so that the butterfly spring 7 and the valve head 6 are completely wrapped in the stepped hole 5-1 of the large diameter section of the valve stem 5.

[0030] The connection structure between the base 4 and the guide sleeve 2 is as follows: the base 4 is a stepped column structure with an upper diameter smaller than the lower diameter, the lower inner hole of the guide sleeve 2 is interference-fitted with the small diameter section of the upper end of the base 4, and the lower end face of the guide sleeve 2 is in contact with the stepped surface of the base 4.

[0031] The specific fitting structure between the guide sleeve 2 and the upper mold 1 and the lower mold 3 is as follows: the inner hole of the guide sleeve 2 is clearance-fitted with the upper mold 1 and the lower mold 3, and the lower end face of the lower mold 3 is in contact with the upper end face of the small diameter section of the base 4; specifically, the gap between the inner hole wall of the guide sleeve 2 and the outer circumferential wall of the upper mold 1 and the lower mold 3 is 0.025mm to 0.075mm.

[0032] The upper mold hole 1-1 has a larger diameter than the center hole of the upper mold 1, and the upper mold hole 1-1 and the center hole of the upper mold 1 are connected by a rounded corner, and the arc formed by the rounded corner presses the upper end of the valve stem 5.

[0033] When assembling the indicator valve, the valve stem assembly must be assembled first. This involves sequentially inserting the butterfly spring 7 and the indicator valve head 6 into the stepped hole 5-1 at the head of the valve stem 5. Then, the valve stem assembly and other components are installed into the valve body. For example... Figure 3 As shown, when the valve stem assembly is completed, the original valve stem 5 head inner hole diameter is Φ13, while the valve head 6 installed in the valve stem 5 has a maximum diameter of Φ14.5, and the butterfly spring outer diameter is Φ14.

[0034] To install the butterfly spring 7 and the indicator valve head 6 into the stepped hole 5-1 of the valve stem 5, the diameter of the valve stem 5's inner hole before assembly must first be determined. Analysis shows that the diameter of the stepped hole 5-1 of the valve stem 5 is designed to be Φ16.2+0.2 0, with a length of 2. To control the valve's stroke, the distance from the end face of the hole to the bottom face is controlled, with dimensions designed to be 10.5+0.1 0 and 6±0.1. Figure 2As shown; at the same time, the designers need to design a device that can be used to press and deform the orifice of the valve stem 5 to Φ13, so that the valve head 6 can be reliably installed into the valve stem 5 and can accurately ensure that the valve stroke meets the requirements of the assembly drawing; therefore, an auxiliary device was designed.

[0035] The installation method for the diesel engine indicator valve stem assembly includes the following steps:

[0036] 1) Optimization and installation of the valve stem assembly: such as Figure 1-2 As shown, the stepped hole 5-1 of the large diameter section of valve stem 5 is optimized so that the diameter of the hole at the orifice position of stepped hole 5-1 ( The diameter of the valve head 6 is greater than the maximum diameter of the valve stem 5 (φ14.5mm), and the hole depth corresponding to the maximum diameter of the valve head 6 is extended (from the original 1mm to 2mm); the butterfly spring 7 is installed in the stepped hole 5-1, and the valve head 6 passes through the butterfly spring 7 and is installed in the stepped hole 5-1, and the position of the maximum diameter of the valve head 6 is located at the opening of the stepped hole 5-1;

[0037] 2) Installation of valve stem assembly and auxiliary device: Fix the guide sleeve 2 to the base 4 and ensure that the fixing structure between the guide sleeve 2 and the base 4 is stable. Then, install the lower mold 3 into the guide sleeve 2 with a clearance fit of 0.025mm to 0.075mm. Next, install the valve stem assembly. Finally, install the upper mold 1 into the guide sleeve 2 with a clearance fit of 0.025mm to 0.075mm. This ensures that the lower mold 3 and the upper mold 1 can move up and down flexibly within the guide sleeve 2, so that the valve stem assembly can be guided when it is pressed.

[0038] In this step, for example Figure 1-5 As shown, a lower die hole 3-1 is concentrically formed at the upper end of the central hole of the lower die 3. The lower die hole 3-1 consists of a tapered hole connected to its central hole and a hole of equal diameter located at the opening. The diameter of the hole of equal diameter (φ20mm) is larger than the diameter of the largest part of the valve stem 5 at the large end. Specifically, an upper die hole 1-1 is concentrically formed at the lower end of the center hole of the upper die 1, and the diameter of the upper die hole 1-1 (φ18.2mm) is smaller than the diameter of the equal-diameter section of the lower die hole 3-1 (φ20mm) but larger than the largest part diameter of the large end of the valve stem 5. During the downward movement of the upper die 1, the arc surface connected by the transition between the upper die hole 1-1 and the center hole of the upper die 1 presses the upper end of the valve stem 5; specifically, the base 4 is made of 45 steel and is heat-treated as a whole, and the hardness of the base 4 is 28-32 HRC; the upper die 1, guide sleeve 2 and lower die 3 are all made of GCr15 steel, and the hardness of the upper die 1, guide sleeve 2 and lower die 3 is 58-62 HRC; specifically, the diameter of the center hole of the upper die 1 ( It is smaller than the maximum diameter of valve head 6 (φ14.5mm) and larger than the diameter of the upper end of valve head 6;

[0039] Pressing: Place the installed structure on the worktable below the press punch, adjust the press pressure, start the press, and stop when the press punch presses against the upper die 1 and moves down until the lower end face of the upper die 1 abuts against the upper end face of the lower die 3. At this time, the upper end of the large end of the valve stem 5 in the valve stem assembly folds inward to enclose the maximum diameter position of the valve head 6 inside it. Figure 3 As shown;

[0040] Among them, ① the tapered hole surface of the lower die hole 3-1 in the lower die 3 is the main working part and has a positioning function. Therefore, this tapered hole surface must have high precision, form and position tolerances, and surface roughness. At the same time, in order to ensure the valve stroke, the inner diameter and length of the large end of this tapered hole surface also need to have high precision requirements, such as... Figure 4 As shown; ② The pressing part of the upper die hole 1-1 in the upper die 1 must be designed as an arc shape, that is, the arc surface formed by the connection between the upper die hole 1-1 and the center hole of the upper die 1 through a rounded transition. This arc surface needs to have a high roughness so that the valve stem 5 does not get stuck during the pressing process, such as Figure 5 As shown; ③ During pressing, the pressing is complete when the press punch cannot move downwards. At this time, the bottom plane of the upper die 1 and the upper plane of the lower die 3 are completely overlapped, thus ensuring the valve stroke.

[0041] 4) After pressing is completed, the press punch moves up and the upper die 1 and valve stem assembly can be removed.

[0042] Safety and stability analysis

[0043] (1) Safety analysis: The device has a simple structure, no special environmental requirements, no electrical or gas assistance, and is lightweight, with no safety hazards.

[0044] (2) Stability analysis: Based on the function of each component of the device and the usage environment, the base 4 is made of 45 steel and is heat-treated as a whole with a hardness of 28-32HRC; the upper mold 1, guide sleeve 2 and lower mold 3 are all made of GCr15 and are quenched and tempered as a whole with a hardness of 58-62HRC, which can ensure the stability of the assembly of the device under long-term operation.

[0045] This invention has been applied to the assembly of the indicator valve stem assembly in diesel engines, solving the problem that the indicator valve stem assembly cannot be directly assembled. Through on-site debugging, tracking and verification, the valve stem assembly assembled using this device can accurately control the length of the inner cavity of the valve stem 5, ensuring the valve stroke and meeting design requirements. Moreover, the assembly is reliable, the on-site operation is simple and convenient, ensuring the assembly quality and efficiency of the indicator valve stem assembly, while reducing the processing difficulty.

[0046] This technical solution optimizes the valve stem assembly installation structure and, with the positioning and guidance of an auxiliary device, uses a press to deform and invert the upper end of the valve stem 5 until the maximum diameter position of the lower end of the butterfly spring 7 and the valve head 6 is completely enclosed within the stepped hole of the large diameter section of the valve stem. This solves the technical problem that the valve stem assembly of the indicator valve cannot be directly assembled. It effectively solves the problems of inserting the valve head 6 into the inner hole of the valve stem 5 and accurately controlling the length of the inner cavity to ensure the valve stroke during the assembly of the indicator valve head 6, valve stem 5, and butterfly spring 7, ensuring smooth assembly of the valve stem assembly. The structure is simple, the on-site operation is simple, and the use is convenient. It reduces the processing and assembly difficulty of the valve stem assembly, effectively ensuring assembly quality and processing efficiency. It provides a reference solution for the assembly technology of similar indicator valve stem assemblies and has high application and promotion value.

[0047] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0048] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An auxiliary device for installing the valve stem assembly of a diesel engine indicator valve, characterized in that: The device includes an upper mold (1), a guide sleeve (2), a lower mold (3), and a base (4). The base (4) has a central hole for the lower half of a valve stem (5) that is vertically positioned with its small end facing downwards to extend into it. The upper end of the central hole has an outwardly flared chamfer. The lower end of the guide sleeve (2) is coaxially fixed to the upper end of the base (4). The lower mold (3) is fitted inside the guide sleeve (2), and the lower end face of the lower mold (3) contacts the upper end face of the base (4). The tapered section at the upper end of the valve stem (5) and the lower half of its large-diameter section are fitted to the lower mold hole (3-1) at the upper end of the central hole of the lower mold (3). The upper mold (1) is fitted to the guide sleeve (2). Inside, and the upper die hole (1-1) at the lower end of the center hole of the upper die (1) is adapted to the upper half of the large diameter section of the valve stem (5). The diameter of the center hole of the upper die (1) is smaller than the maximum diameter of the valve head (6) and larger than the diameter of the upper end adjacent to the maximum diameter position of the valve head (6). The upper end of the upper die (1) extends out of the guide sleeve (2). When the punch of the press presses the upper die (1) downward until the upper die (1) moves down to its lower end face and contacts the upper end face of the lower die (3), the upper end of the valve stem (5) is deformed and turned inward to completely wrap the butterfly spring (7) and the maximum diameter position of the lower end of the valve head (6) inside the stepped hole (5-1) of the large diameter section of the valve stem (5). The base (4) is a stepped column structure with an upper diameter smaller than the lower diameter. The inner hole at the lower end of the guide sleeve (2) is interference-fitted with the small diameter section at the upper end of the base (4), and the lower end face of the guide sleeve (2) is in contact with the stepped surface of the base (4). The inner hole of the guide sleeve (2) is clearance-fitted with the upper mold (1) and the lower mold (3), and the lower end face of the lower mold (3) is in contact with the upper end face of the small diameter section of the base (4).

2. The auxiliary device for installing the diesel engine indicator valve stem assembly according to claim 1, characterized in that: The gap between the inner wall of the guide sleeve (2) and the outer circumferential wall of the upper mold (1) and the lower mold (3) is 0.025mm to 0.075mm.

3. The auxiliary device for installing the diesel engine indicator valve stem assembly according to any one of claims 1-2, characterized in that: The diameter of the upper die hole (1-1) is larger than the diameter of the center hole of the upper die (1), and the upper die hole (1-1) and the center hole of the upper die (1) are connected by a rounded corner, and the arc formed by the rounded corner presses the upper end of the valve stem (5).

4. A method for installing a diesel engine indicator valve stem assembly using the auxiliary device for installing a diesel engine indicator valve stem assembly as described in claim 1, characterized in that... Includes the following steps: 1) Optimization and installation of valve stem assembly: Optimize the stepped hole (5-1) of the large diameter section of valve stem (5) so that the diameter of the hole at the opening of the stepped hole (5-1) is greater than the maximum diameter of the valve head (6) installed in the valve stem (5), and extend the hole depth corresponding to the maximum diameter of the valve head (6); install the butterfly spring (7) into the stepped hole (5-1), and make the valve head (6) pass through the butterfly spring (7) and install it into the stepped hole (5-1), and the maximum diameter of the valve head (6) is located at the opening of the stepped hole (5-1); 2) Installation of valve stem assembly and auxiliary device: Fix the guide sleeve (2) on the base (4) and ensure that the fixing structure between the guide sleeve (2) and the base (4) is stable. Then, install the lower mold (3) into the guide sleeve (2), then install the valve stem assembly, and finally install the upper mold (1) into the guide sleeve (2). It is necessary to ensure that the lower mold (3) and the upper mold (1) can move up and down flexibly in the guide sleeve (2). 3) Pressing: Place the installed structure on the worktable below the press punch, start the press, and stop when the press punch presses against the upper die (1) and moves down to the lower end face of the upper die (1) against the upper end face of the lower die (3). At this time, the upper end of the large end of the valve stem (5) in the valve stem assembly is turned inward to wrap the valve head (6) at its maximum diameter position inside. 4) After pressing is completed, the press punch moves up and the upper die (1) and valve stem assembly can be removed.

5. The method for installing the diesel engine indicator valve stem assembly according to claim 4, characterized in that: The lower mold (3) has a lower mold hole (3-1) concentrically formed at the upper end of the center hole. The lower mold hole (3-1) consists of a tapered hole connected to its center hole and an equal diameter hole located at the opening position. The diameter of the equal diameter hole is larger than the largest part diameter of the large end of the valve stem (5).

6. The method for installing the diesel engine indicator valve stem assembly according to claim 5, characterized in that: The upper die (1) has a concentric upper die hole (1-1) at the lower end of the center hole. The diameter of the upper die hole (1-1) is smaller than the diameter of the equal-diameter section of the lower die hole (3-1) but larger than the largest part diameter of the valve stem (5). During the process of the press punch pressing the upper die (1) downward, the arc surface connected by the upper die hole (1-1) and the center hole of the upper die (1) presses the upper end of the valve stem (5).

7. The method for installing the diesel engine indicator valve stem assembly according to claim 6, characterized in that: The base (4) is made of 45 steel and is heat-treated as a whole, and the hardness of the base (4) is 28-32HRC; the upper mold (1), guide sleeve (2) and lower mold (3) are all made of GCr15 steel, and the hardness of the upper mold (1), guide sleeve (2) and lower mold (3) is 58-62HRC.

8. The method for installing the diesel engine indicator valve stem assembly according to any one of claims 4-7, characterized in that: The diameter of the center hole of the upper mold (1) is smaller than the maximum diameter of the valve head (6) and larger than the diameter of the upper end of the valve head (6).

Images