GB2127511A

GB2127511A - Pipe connector

Info

Publication number: GB2127511A
Application number: GB08324110A
Authority: GB
Inventors: Kaoru Nakamura
Original assignee: Aisin Seiki Co Ltd
Current assignee: Aisin Corp
Priority date: 1982-09-23
Filing date: 1983-09-08
Publication date: 1984-04-11
Also published as: JPS5949082U; GB2127511B; GB8324110D0

Abstract

A connector is provided for connecting a metal tube 19 to a port of a hydraulic pressure cylinder 13, the pressure cylinder being made of resin. A metal insert member 18 is fixed in the resin and has a thread 18a co-operating with a thread 20a of a nut 20 rotatably mounted on the tube. A metal union member 25 has a shaft portion 25b force fitted into a small diameter portion 23 of the port and a head member 25a. The head member 25a has a surface for seating on a shoulder 24 between large and intermediate diameter portions 21 and 22 of the port and a conical surface for seating a flared end of the tube 19. A sealing member 27 lies between the shaft portion 25b of the union member 25 and the intermediate diameter portion 22 of the port. <IMAGE>

Description

SPECIFICATION A connector The invention relates to a connector for connecting a metal tube to a port of a hydraulic pressure cylinder formed from resin material.

Hydraulic pressure cylinders, such as those used as brake master cylinders or clutch master cylinders in automotive vehicles, are often formed from moulded resin material to reduce their weight. The connection of a metal tube to such a hydraulic pressure cylinder, to provide a hydraulic passage from the pressure cylinder to a hydraulic pressure device such as a wheel brake cylinder to be operated thereby, gives rise to various difficulties. The connection may be insufficiently tight because a thread formed in the resin is damaged by the co-operating thread on the metal tube if too much torque is applied or because of the difference in the thermal expansion coefficients of the resin and the metal.

The invention provides a connector for connecting a metal tube to a port of a hydraulic pressure cylinder made of resin material, the connector comprising a tubular metal insert member axially and circumferentially fixed in the port, a metal nut rotatably mounted on the tube and provided with a thread for engagement with a thread on the insert member, a tubular metal union member having a shaft portion for force fitting in a small diameter portion of the port and a head portion, the head portion having a surface for seating on a shoulder between a large diameter portion and an intermediate diameter portion of the port and a surface for seating the tube, and a sealing member between the shaft portion of the union member and the intermediate diameter portion of the port.

The invention is illustrated by the drawings, of which: Figure 1 is a side elevation of a hydraulic pressure cylinder fitted with a connector according to the invention; Figure 2 is an enlarged sectional view taken along the line Il-Il in Figure 1; and Figure 3 is a sectional view similar to Figure 2, but showing a second embodiment of a connector according to the invention.

With reference to Figure 1 of the drawings, a master cylinder generally designated 10 for a hydraulic brake or clutch release system of an automotive vehicle comprises a cap 11, a reservoir 12, a cylinder body 13, and a flange 14 for mounting the master cylinder 10 on a vehicle body (not shown). The reservoir 12, cylinder body 13 and flange 14 are formed integrally from a moulded resin material such as 6-nylon combined with short glass fibres. A push rod 15 provides an operative mechanical connection between a pedal (not shown) on the vehicle body and a piston (not shown) slidably disposed within the cylinder body 13.

An outlet port 1 7 of the master cylinder 10 extends through a boss 16 formed on the cylinder body 13. As shown in Figure 2, a tubular metal insert member 18 is positioned within the boss 16. The insert member 18 has a serrated annular land 1 8b on its outer periphery for fixing the insert member 18 within the boss 16 in both axial and circumferential directions. The insert member 18 is formed with a female thread 18a which is engageable with a male thread 20a on a nut 20.

The nut 20 is made of metal and is rotatably mounted on a metal tube 19. The tube 19 provides a hydraulic connection between the master cylinder 10 and a wheel brake cylinder or clutch release cylinder 30.

The port 17 has a large diameter portion 21 adjacent to the inner end of the female thread 1 8a a small diameter portion 23 inwardly of the large diameter portion 21, an intermediate diameter portion 22 between the portions 21 and 23, and an annular shoulder 24 between the portions 21 and 22. The shoulder 24 is formed on the insert member 18 and provides a conical seat for a head portion 25a of a metal tubular union member 25.

The union member 25 has a shaft portion 25b which is press fitted into the small diameter portion 23 of the port 17 to fix the union member 25 to the cylinder body 13. The head portion 25a of the union member 25 is formed at its end remote from the shaft portion 25b with a conical surface on which a flared end portion 1 9a of the tube 19 is sealingly seated by the axial force exerted on it by the nut 20. The axial force is generated through thread-engagement between the threads 18a and 20a upon applying torque to the nut 20 when connecting the tube. Both threads 18a and 20a are metal so that there is no damage to a resin thread by a stronger metal one.

To prevent fluid leakage through the clearance between the shaft portion 25a of the union member 25 and the small diameter portion 23, occurring because of the differing thermal expansion coefficients of the resin cylinder body 13 and the metal union member 25, a sealing ring 27 made of rubber is provided between the shaft portion 25a of the union member 25 and the intermediate diameter portion 22 of the port 17.

The sealing ring 27 is inserted into the port 17 together with the member 25 during assembly of the connector. The conical shoulder 24 acts as a guide surface for insertion of the sealing ring 27 into the intermediate diameter portion 22 of the port 17, and thereby prevents the ring 1 7, 27 from being damaged.

In Figure 3, parts corresponding to those illustrated in Figure 2 are identified by the reference numerals used in Figure 2 with the addition of 100. The important difference between the embodiments of Figures 2 and 3 is that the shoulder 124 between the large diameter portion 121 and the intermediate diameter portion 122 of the port is formed in the resin of the boss rather than on the insert member 118.

1. A connector for connecting a metal tube to a port of a hydraulic pressure cylinder made of resin material, the connector comprising a tubular metal

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION A connector The invention relates to a connector for connecting a metal tube to a port of a hydraulic pressure cylinder formed from resin material. Hydraulic pressure cylinders, such as those used as brake master cylinders or clutch master cylinders in automotive vehicles, are often formed from moulded resin material to reduce their weight. The connection of a metal tube to such a hydraulic pressure cylinder, to provide a hydraulic passage from the pressure cylinder to a hydraulic pressure device such as a wheel brake cylinder to be operated thereby, gives rise to various difficulties. The connection may be insufficiently tight because a thread formed in the resin is damaged by the co-operating thread on the metal tube if too much torque is applied or because of the difference in the thermal expansion coefficients of the resin and the metal. The invention provides a connector for connecting a metal tube to a port of a hydraulic pressure cylinder made of resin material, the connector comprising a tubular metal insert member axially and circumferentially fixed in the port, a metal nut rotatably mounted on the tube and provided with a thread for engagement with a thread on the insert member, a tubular metal union member having a shaft portion for force fitting in a small diameter portion of the port and a head portion, the head portion having a surface for seating on a shoulder between a large diameter portion and an intermediate diameter portion of the port and a surface for seating the tube, and a sealing member between the shaft portion of the union member and the intermediate diameter portion of the port. The invention is illustrated by the drawings, of which: Figure 1 is a side elevation of a hydraulic pressure cylinder fitted with a connector according to the invention; Figure 2 is an enlarged sectional view taken along the line Il-Il in Figure 1; and Figure 3 is a sectional view similar to Figure 2, but showing a second embodiment of a connector according to the invention. With reference to Figure 1 of the drawings, a master cylinder generally designated 10 for a hydraulic brake or clutch release system of an automotive vehicle comprises a cap 11, a reservoir 12, a cylinder body 13, and a flange 14 for mounting the master cylinder 10 on a vehicle body (not shown). The reservoir 12, cylinder body 13 and flange 14 are formed integrally from a moulded resin material such as 6-nylon combined with short glass fibres. A push rod 15 provides an operative mechanical connection between a pedal (not shown) on the vehicle body and a piston (not shown) slidably disposed within the cylinder body 13. An outlet port 1 7 of the master cylinder 10 extends through a boss 16 formed on the cylinder body 13. As shown in Figure 2, a tubular metal insert member 18 is positioned within the boss 16. The insert member 18 has a serrated annular land 1 8b on its outer periphery for fixing the insert member 18 within the boss 16 in both axial and circumferential directions. The insert member 18 is formed with a female thread 18a which is engageable with a male thread 20a on a nut 20. The nut 20 is made of metal and is rotatably mounted on a metal tube 19. The tube 19 provides a hydraulic connection between the master cylinder 10 and a wheel brake cylinder or clutch release cylinder 30. The port 17 has a large diameter portion 21 adjacent to the inner end of the female thread 1 8a a small diameter portion 23 inwardly of the large diameter portion 21, an intermediate diameter portion 22 between the portions 21 and 23, and an annular shoulder 24 between the portions 21 and 22. The shoulder 24 is formed on the insert member 18 and provides a conical seat for a head portion 25a of a metal tubular union member 25. The union member 25 has a shaft portion 25b which is press fitted into the small diameter portion 23 of the port 17 to fix the union member 25 to the cylinder body 13. The head portion 25a of the union member 25 is formed at its end remote from the shaft portion 25b with a conical surface on which a flared end portion 1 9a of the tube 19 is sealingly seated by the axial force exerted on it by the nut 20. The axial force is generated through thread-engagement between the threads 18a and 20a upon applying torque to the nut 20 when connecting the tube. Both threads 18a and 20a are metal so that there is no damage to a resin thread by a stronger metal one. To prevent fluid leakage through the clearance between the shaft portion 25a of the union member 25 and the small diameter portion 23, occurring because of the differing thermal expansion coefficients of the resin cylinder body 13 and the metal union member 25, a sealing ring 27 made of rubber is provided between the shaft portion 25a of the union member 25 and the intermediate diameter portion 22 of the port 17. The sealing ring 27 is inserted into the port 17 together with the member 25 during assembly of the connector. The conical shoulder 24 acts as a guide surface for insertion of the sealing ring 27 into the intermediate diameter portion 22 of the port 17, and thereby prevents the ring 1 7, 27 from being damaged. In Figure 3, parts corresponding to those illustrated in Figure 2 are identified by the reference numerals used in Figure 2 with the addition of 100. The important difference between the embodiments of Figures 2 and 3 is that the shoulder 124 between the large diameter portion 121 and the intermediate diameter portion 122 of the port is formed in the resin of the boss rather than on the insert member 118. CLAIMS

1. A connector for connecting a metal tube to a port of a hydraulic pressure cylinder made of resin material, the connector comprising a tubular metal insert member axially and circumferentially fixed in the port, a metal nut rotatably mounted on the tube and provided with a thread for engagement with a thread on the insert member, a tubular metal union member having a shaft portion for force fitting in a small diameter portion of the port and a head portion, the head portion having a surface for seating on a shoulder between a large diameter portion and an intermediate diameter portion of the port and a surface for seating the tube, and a sealing member between the shaft portion of the union member and the intermediate diameter portion of the port.

2. A connector according to claim 1 in which the head portion of the union member has a conical surface for seating a flared end of the tube.

3. A connector according to claim 1 or claim 2 in which the insert member is fixed in the port by engagement of a serrated annular land provided on the insert member with the resin material of the port.

4. A connector according to any preceding claim in which the large diameter portion of the port and the shoulder between it and the intermediate diameter portion of the port are formed by a part of the insert member.

5. A connector according to any preceding claim in which the large diameter portion of the port and the shoulder between it and the intermediate diameter portion of the port are formed in the resin material of the port.

6. A connector for connecting a metal tube to a port of a hydraulic pressure cylinder made of resin material, the connector being substantially as described herein with reference to Figure 2 of the drawings.

7. A connector for connecting a metal tube to a port of a hydraulic pressure cylinder made of resin material, the connector being substantially as described herein with reference to Figure 3 of the drawings.