JPH0512672U - Joint of ceramic shaft and metal cylinder - Google Patents

Abstract

(57) [Abstract] [Purpose] A ceramic rod and a metal that are fitted together by inserting a round rod-shaped ceramic rod into a metal tubular member, and are joined together with an adhesive in the clearance between the ceramic rod and the metal tubular member. In the joint structure with the cylindrical body, even if a bending moment is applied to the tip end of the ceramic shaft body, the ceramic shaft base end is set so as to easily absorb the deformation to prevent damage to the ceramic shaft base end side. [Composition] A round rod-shaped ceramic shaft body is fitted in a metal cylinder body, and a ceramic shaft body and a metal cylinder body are bonded together by interposing an adhesive in the clearance between the ceramic shaft body and the metal cylinder body. In the body, the clearance is set to 10 μm or more in diameter difference, and the elastic modulus of the adhesive is set.
It is a joined body of a ceramic shaft body and a metal cylinder body, which is set to 6.0 × 10 ⁵ kgf / cm ² or less.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 According to the present invention, a round rod-shaped ceramic shaft body is fitted in a metal cylinder body, and a ceramic shaft body and a metal cylinder body are bonded together by interposing an adhesive in the clearance between the ceramic shaft body and the metal cylinder body. It relates to the structure, and particularly to the joint between the plunger of the plunger pump and the metal cylinder.

[0002]

[Prior Art]

 A conventional example of a joint structure of a ceramic shaft body and a metal cylinder body in which a round rod-shaped ceramic shaft body is fitted in a metal cylinder body and an adhesive agent is interposed in the clearance between the ceramic shaft body and the metal cylinder body for bonding. There is a joint between the plunger of the plunger pump and the metal cylinder. As a concrete example, there is Japanese Utility Model Laid-Open No. 62-97281 "Plunger for reciprocating pump", and a ceramic material is used as the plunger of the plunger pump with a focus on abrasion resistance.

However, due to the structure of the plunger pump, it is difficult to use a ceramic material as a member for transmitting the driving force from the driving part because it is a brittle material, and the sliding part is made of a ceramic material to drive the driving part. The part that transmits the force was made of a metal material, and the ceramic plunger was joined to the metal cylinder by adhesion or shrink fitting.

[0004]

[Problems to be solved by the device]

 However, with such a structure in which a ceramic plunger is internally fitted and joined to a metal cylinder, if there is slight vibration during operation of the ceramic plunger or misalignment of the shaft core during assembly, a bending moment is added to the tip of the ceramic plunger. As a result, tensile stress acts on the joint between the ceramic plunger and the metal cylinder on the proximal end side of the ceramic plunger, and the ceramic plunger frequently breaks at the joint.

[0005]

[Means for Solving the Problems]

Therefore, in consideration of the above circumstances, the present invention sets the ceramic shaft base end so that the deformation can be easily absorbed even if a bending moment is applied to the ceramic shaft end, thereby preventing damage on the ceramic shaft base end side. In order to prevent this, by setting the clearance of the metal cylinder joined to the ceramic shaft to a predetermined appropriate value, and also setting the elastic modulus of the adhesive intervening in the clearance to an appropriate value, the load from the outside is set. It relaxes the tensile stress at the joint between the ceramic shaft and the metal cylinder to be used under a certain load, and reduces the damage rate during operation. Specifically, the clearance between the ceramic shaft body and the metal cylinder to be joined is preferably 10 μm or more in diameter difference, and the elastic modulus of the adhesive is preferably 6.0 × 10 ⁵ kgf / cm ² or less.

[0006]

【Example】

Hereinafter, the present invention will be described in detail with reference to specific embodiments shown in the drawings. As shown in FIG. 1, a round rod-shaped ceramic plunger 1 is made of aluminum ceramic having an Al ₂ O ₃ purity of 99%, and is internally fitted into a metal cylinder 2 such as a stainless steel material and bonded with an adhesive 4. Further, the hole 3 on the base end side of the metal cylinder body 2 is a pin hole for pivotally mounting the connecting rod.

Regarding the clearance between the ceramic plunger 1 and the metal cylinder 2, the adhesive 4 having a modulus of elasticity of 6.0 × 10 ⁵ kgf / cm ² or less was used, and the clearance between the shellac plunger 1 and the metal cylinder 2 was 5 μm. , 10 μm, 20 μm, 30 μm, 40 μm, and 50 μm, and evenly intervene and join the joining sites. The ceramic cylinder 1 and the metal cylinder 2 are joined together to fix the metal cylinder 2, and a constant static load is applied to the outer peripheral surface near the tip surface of the ceramic plunger 1 at a crosshead speed of 0.5 mm / sec. In Fig. 1, the load that causes breakage at the joint between the ceramic plunger 1 and the metal cylinder 2 was measured by an autograph. In each experiment, the number of samples was 5, and the average value was used as the breakage load value under each set value condition. The clearance mentioned here is the difference between the outer diameter of the ceramic plunger 1 and the inner diameter of the metal cylinder 2.

The experimental results were as shown in Table 1.

[0009]

[Table 1]

From these results, the relationship between the clearance between the ceramic plunger 1 and the metal cylinder 2 and the breaking load is 92.5 kgf at 5 μm clearance, 127.8 kgf at 10 μm clearance, 135.2 kgf at 20 μm clearance, 138.6 kgf at 30 μm clearance, It shows 135.4kgf at 40μm, 137.3kgf at 50μm, and 138.1kgf at 60μm, showing almost the same breaking load with a clearance of 10μm or more, but showing a small breaking load with a clearance of 10μm or less. There is. Therefore, it is possible to greatly improve the breakage strength by setting the clearance to 10 μm or more. However, it is desirable that the clearance be 100 μm or less, and if it is more than 100 μm, the dimensional accuracy is poor and the adhesive strength is reduced.

Elastic Modulus of Adhesive 4 With the clearance between the ceramic plunger 1 and the metal cylinder 2 being set to 10 μm, the same experiment as described above was conducted using five types of epoxy adhesives having different elastic moduli. The experiment was as shown in Table 2.

[0012]

[Table 2]

The adhesive 4 has an elastic modulus of 6.0 × 10 ⁸ kgf / cm ² , a breaking load of 128.1 kgf, 6.0 × 10 ⁵ kgf / cm ² of 165.9 kgf, and 3.0 × 10 ⁵ kgf / cm ² of 175.5 kgf, 6.0 180.2 kgf at × 10 ⁴ kgf / cm ² , 178.8 kgf at 3.0 × 10 ⁴ kgf / cm ² , and a large breakage is caused by interposing an adhesive 4 having an elastic modulus of 6.0 × 10 ⁵ kgf / cm ² or less. It becomes possible to improve the strength. This is because the deformable adhesive 4 having an elastic modulus of 6.0 × 10 ⁵ kgf / cm ² or less absorbs the deformation, relaxes the tensile stress, and lowers the damage rate.

Further, although the ceramic plunger 1 is made of alumina ceramic in the above-mentioned embodiment, various ceramics such as zirconia, silicon carbide, and silicon nitride can be used.

[0015]

[Effect of the device]

 According to the present invention, the clearance between the ceramic shaft and the metal cylinder is properly set, and further, the elastic modulus of the adhesive interposed in the clearance is set to an appropriate value. It has become possible to improve the breakage strength of the joint between the and the metal cylinder and reduce the probability of breakage during operation. Further, in the present invention, the effect can be expected even if the clearance setting between the ceramic shaft body and the metal cylindrical body and the elastic modulus setting of the intervening adhesive are applied individually, and if they are applied simultaneously, the effect is synergistic. Will be reflected.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a main part of a plunger pump according to a specific embodiment showing the present invention.

[Explanation of symbols]

 1 ... Ceramic plunger (example of ceramic shaft) 2 ... Metal cylinder 4 ... Adhesive

Claims (1)

[Scope of utility model registration request] 1. A ceramic shaft body and a metal cylinder body in which a round rod-shaped ceramic shaft body is internally fitted in a metal cylinder body and bonded by interposing an adhesive in a clearance between the ceramic shaft body and the metal cylinder body. In the joined body of 1, the clearance is set to 10 μm or more in diameter difference, and the elastic modulus of the adhesive is set to 6.0 × 10 ⁵ kgf / cm ² or less, and a ceramic shaft body and a metal cylinder body. Zygote.