JPH07103337A - Seal ring manufacturing method for floating seal - Google Patents

Abstract

PURPOSE:To dispense with work for eliminating distortion due to a thermal treatment so as to enhance productivity by making a seal ring base body having a cylindrical portion and a flange portion by sheeting, followed by induction hardening the flange portion of the base body with the cylindrical portion thereof supported. CONSTITUTION:A pair of seal sings 3, 3 are air-tightly fitted to the inner circumferential surface 1a of a housing 1 on a stationary side and the inner circumferential surface 2a of a housing 2 on a rotating side, respectively, via load rings 4 made of rubber, so as to prevent leakage of lubricant which is sealed by their sliding motion 5. In manufacturing the seal rings 3 in the thus constituted seal device, a ring-like base plate made of an SK-7 material or the like is bent in a predetermined thickness by a press machine, thus providing a seal ring base body 13 having a cylindrical portion 11 and a flange portion 12. Subsequently, the base body 13 is subjected to an induction hardening thermal treatment where it is heated by a high frequency induction heating coil 16 while a turntable 14 is rotated with the base body 13 supported by a support jig 15, followed by cooling.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a seal ring which constitutes a floating seal mounted on a rotating portion of a track type traveling device of a tracked vehicle such as a bulldozer or a hydraulic excavator.

[0002]

2. Description of the Related Art As a track type traveling device of a tracked vehicle such as a bulldozer or a hydraulic excavator, one in which a crawler belt is wound around an activating wheel and an idle wheel and the crawler belt is guided by upper and lower rolling wheels is known. A floating seal is attached to the rotating parts of the starter wheel, idler wheel, and upper and lower wheels to prevent leakage of the enclosed lubricating oil and prevent mud and sand from entering.

The above-mentioned floating seal hermetically supports a pair of seal rings on the inner peripheral surfaces of the stationary side housing and the rotating side housing via rubber load rings, respectively.
The opposite end faces of the pair of seal rings are closely slid together, and the sliding faces of the seal rings have high hardness to improve durability.

As a method of manufacturing the aforementioned seal ring,
It is known that a material is cast into a base body having a predetermined cross-sectional shape, the base body is machined, then the whole body is quenched and heat treated for tempering, and then machined again.

[0005]

According to such a manufacturing method, since many steps such as a casting step, a machining step, a heat treatment step, and a machining step are required, the manufacturing cost becomes high. Further, a large amount of strain is generated due to the heat treatment, and it is necessary to increase the machining allowance after the heat treatment to remove the strain, resulting in a decrease in yield and an increase in processing cost, resulting in an increase in cost. It should be noted that press quench equipment may be used in order to reduce the strain associated with the heat treatment, but this press quench equipment is a relatively large-scale equipment and is costly.

Therefore, an object of the present invention is to provide a method for manufacturing a seal ring of a floating seal, which can solve the above-mentioned problems.

[0007]

A seal ring base body 13 having a cylindrical portion 11 and a flange portion 12 is produced by sheet metal working, and the flange portion 12 is induction hardened while the cylindrical portion 11 of the seal ring base body 13 is supported. Seal ring manufacturing method for floating seals.

[0008]

[Operation] Since the seal ring base body 13 having the tubular portion 11 and the flange portion 12 is formed by sheet metal working and the seal ring base body 13 is induction hardened, the number of manufacturing steps is small and the manufacturing cost is low. Since it is not necessary to remove the distortion caused by the above, machining as a post-process becomes unnecessary, the yield is improved, and the processing cost can be reduced.

[0009]

[Example] As shown in Fig. 1, the stationary housing 1
A pair of seal rings 3 and 3 are airtightly provided on the inner peripheral surface 1a of the rotor 1 and the inner peripheral surface 2a of the rotation-side housing 2 via a rubber load ring 4, respectively. The sliding seal 5 prevents the lubricating oil enclosed by the sliding contact from leaking and prevents mud and sand from entering to form a floating seal.

Next, a method of manufacturing the seal ring 3 will be described. As shown in FIG. 2, for example, a ring-shaped substrate 10 having a predetermined thickness and a predetermined shape made of SK-7 material is bent by a press machine A, and a cylindrical portion 11 and a flange portion are formed as shown in FIG. The seal ring base 13 having the reference numeral 12 is provided. For example, the thickness t of the seal ring base 13 is 2 mm, the outer diameter d of the tubular portion 11 is 96 mm, the outer diameter D of the flange portion 12 is 109 mm, the height H is 8.2 mm, and the cylindrical portion 11 and the flange portion 12 are The angle θ is right. The flat plate may be punched into a ring shape and bent at the same time to form the seal ring base 13. That is, the seal ring substrate may be prepared by sheet metal working.

The seal ring base 13 is set in the induction hardening apparatus B shown in FIG. 4, and the flange portion 12 is induction hardened. The induction hardening apparatus B is a turntable 14
It is composed of a support jig 15 installed above and a ring-shaped high-frequency induction heating coil 16 equipped with a spray jack. The support jig 15 has a ring-shaped outer peripheral guide 17 and a disc-shaped inner peripheral guide 18 to form an annular gap. The cylindrical portion 11 of the seal ring base 13 is fitted and supported in the annular gap 19 and the flange portion 12 is fitted and supported in the annular recess 17a of the outer peripheral guide 17. The size of the annular gap 19 between the outer peripheral guide 17 and the inner peripheral guide 18 is the thickness of the cylindrical portion 11 of the seal ring base 13 plus the allowable tolerance. The high frequency induction heating coil 16 is opposed to the flange portion 12 of the seal ring substrate 13 with a predetermined space (for example, 1 mm).

As described above, while the seal ring substrate 13 is supported by the supporting jig 15, the turntable 14 is rotated while being heated by the high frequency induction heating coil 16 and then cooled by a refrigerant to be induction hardened (heat treated), and thereafter. The outer peripheral portion of the flange portion 12 is lapped to form a seal ring. Here, the induction hardening condition is a frequency of 150K.
Hz, voltage 6.5 KV, electric power 30 KW, heating time 6 seconds, cooling medium is water and cooling time is 4 seconds. in this way,
Uniform induction hardening can be performed by rotating the turntable 14 and induction hardening.

By induction hardening as described above, the cylindrical portion 11 and the flange portion 12 of the seal ring base 13 are formed as shown in FIG.
Inside diameter d ₁ of the cylindrical portion 11 distortion occurs in the direction indicated by a broken line
Becomes smaller and the angle θ formed by the cylindrical portion 11 and the flange portion 12 becomes larger than a right angle, but since the cylindrical portion 11 is fitted and restrained in the annular gap 19 of the support jig 15, its inner diameter d The change in ₁ is small and the angle θ formed by the cylindrical portion 11 and the flange portion 12 is larger than a right angle, as shown in FIG. 6, the flange portions 12 and 12 of the pair of seal rings 13 are tapered. Since the outer peripheral portion 12a comes into contact with each other, the original function of the floating seal is exhibited, and special processing is not required, which is preferable.

That is, the floating seal has a pair of end faces facing each other in a tapered shape so that the outer seals come into contact with each other in the function thereof. Conventionally, the floating seal was machined into a tapered shape. However, according to the present invention, the heat treatment is performed. As a result, the taper shape eliminates the need for taper processing after heat treatment as in the conventional case.

Next, when a change in the inner diameter d ₁ of the cylindrical portion 11 of the seal ring base body 13 induction-hardened as described above and a change in the angle θ formed by the cylindrical portion 11 and the flange portion 12 were measured, the cylindrical portion 11 The change in the inner diameter d _{1 of the above} was as shown in Table 1 below. However, the inner diameter d ₁ was measured at four positions at 90 ° intervals in the circumferential direction.

[0016]

[Table 1]

The angle θ formed by the cylindrical portion 11 and the flange portion 12, in this case, the change in the height H of the seal ring base body 13 (warpage of the flange portion 12) was measured, and the results are shown in Table 2 below. . However, the height H was measured at eight locations at equal intervals in the circumferential direction.

[0018]

[Table 2]

[0019]

The seal ring base 13 having the tubular portion 11 and the flange 12 is prepared, and the seal ring base 1 is manufactured.
3 can be induction-hardened, so the number of manufacturing processes is small and the manufacturing cost is low. Since it is not necessary to remove the distortion caused by heat treatment, the machining process as a post-process is not required, the yield is improved, and the processing cost is low. it can.

[Brief description of drawings]

FIG. 1 is a sectional view of a floating seal.

FIG. 2 is an explanatory view of processing a seal ring base.

FIG. 3 is a cross-sectional view of a seal ring base.

FIG. 4 is a sectional view of an induction hardening apparatus.

FIG. 5 is an explanatory diagram of distortion caused by quenching of the seal ring substrate.

FIG. 6 is an explanatory diagram of a contact state of a pair of seal rings.

[Explanation of symbols]

11 ... Cylindrical part, 12 ... Flange part, 13 ... Seal ring base, 14 ... Turntable, 15 ... Support jig, 16 ...
High frequency induction heating coil, 17 ... outer peripheral guide, 18 ... inner peripheral guide, 19 ... annular gap.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Hasegawa 2-11-24 Chifune, Nishiyodogawa-ku, Osaka-shi, Osaka Prefecture Osaka Plant (72) Inventor Haruhiko Ando 3-1, Ueno, Hirakata-shi, Osaka Prefecture -1 Komatsu Ltd. Osaka Plant (72) Inventor Kazuhide Okawa 3-1-1 Ueno, Hirakata City, Osaka Prefecture Komatsu Ltd. Osaka Plant

Claims (2)

[Claims] 1. A seal ring substrate 13 having a cylindrical portion 11 and a flange portion 12 is produced by sheet metal working, and the flange portion 12 is induction hardened in a state of supporting the cylindrical portion 11 of the seal ring substrate 13 to form a seal ring. A method for manufacturing a seal ring for a floating seal, comprising: 2. The cylindrical portion 11 of the seal ring base 13 is fitted into and supported by the annular gap 19 of the support jig 15 so that the flange portion 12 is oriented upward. The method for producing a seal ring of a floating seal according to claim 1, wherein the flange portion 12 is quenched by the high frequency induction heating coil 16 while rotating the.