JPH0720475Y2 - Electric fusion type plastic pipe joint and its sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a plastic pipe joint for connecting plastic pipes by electric fusion, and in particular, an electric fusion type plastic pipe joint for controlling electric fusion with a sensor, And its sensors.

[Prior Art] Conventionally, for example, an electric fusion type plastic pipe joint using a temperature sensor and its temperature sensor are disclosed in Japanese Utility Model Laid-Open No. 64-49.
No. 97, which is shown in a sectional view in FIG.

The plastic pipe joint 1 comprises a substantially cylindrical plastic joint body 10 and a heating wire 20 wound around and embedded in the inner peripheral surface portion thereof.
And a connector pin 21 having one end connected to each of both ends of the heating wire 20 and the other end protruding from the outer peripheral surface of the plastic joint body 10, and a thermocouple hole on the outer peripheral surface of the plastic joint body 10. 19 is formed.

The plastic pipe fitting 1 is connected with the plastic pipe 2 inserted therein. The temperature sensor is a thermocouple 39, and the thermocouple 39, the holder 40, and the connector bush 41 constitute the connector 3. The connector bush 41 has a cylindrical portion that fits into the connector pin 21 of the plastic pipe joint 1, and is connected to the electric wire 43 on the axially opposite side of this cylindrical portion. The connector bush 41 and the thermocouple 39 are in a positional relationship parallel to each other, and they are integrated by the holder 40.

Next, an operation / procedure for connecting the plastic pipe joint 1 and the plastic pipe 2 will be described.

First, the plastic pipe joint 1 and the plastic pipe 2
Insert.

Secondly, the connector 3 is attached to the plastic pipe joint 1. At this time, the connector pin 21 and the connector bush
41, and the tip of the thermocouple 39 enters the thermocouple hole 19.

Thirdly, an electric current is passed through the heating wire 20 through the connector bush 41 and the connector pin 21 via a separate controller (not shown). At this time, the temperature at the bottom of the thermocouple hole 19 is measured by the thermocouple 39.

Fourth, when the temperature at the bottom of the thermocouple hole 19 reaches the set temperature, the current is stopped.

Finally, fifthly, the connector 3 is removed from the plastic pipe joint 1 to complete the connection.

[Problems to be Solved by the Invention] Conventional plastic pipe joint 1 and thermocouple described above
39 has the following problems. That is, when the connector 3 is attached to the plastic pipe joint 1, the thermocouple 39 is pushed by the force pushing the connector 3 to the plastic pipe joint 1.
The contact pressure between the most advanced surface and the bottom surface of the thermocouple hole 19 sometimes fluctuated greatly.

When this contact pressure is high, the slope of the temperature rise curve with time elapses becomes higher and tends to become tighter than when it is low. Therefore, if the contact pressure varies, the gradient of the temperature rise curve also varies, and the time to reach a certain set temperature varies. That is, the time during which the current was applied to the plastic pipe joint 1 varied, and a good connection result could not be obtained.

Further, the tip surface of the thermocouple 39 and the bottom surface of the thermocouple hole 19 may be separated from each other, and in this case, the time for supplying the current to the plastic pipe joint 1 was too long, and a good connection result could not be obtained.

An object of the present invention is that the contact pressure between the sensor leading end surface and the bottom surface of the plastic fitting sensor hole or the distance between them does not vary, or the variation is small, depending on the force of mounting the connector to the plastic fitting. A plastic fitting and its sensor are provided.

[Means for Solving the Problems] The present invention has a substantially cylindrical plastic joint body, a heating wire wound around and embedded in an inner peripheral surface portion of the plastic joint body, and one end at each end of the heating wire. A connector pin that connects the parts and the other end of which protrudes from the outer peripheral surface of the plastic joint body, and comprises an electric fusion-bonded plastic pipe joint in which a hole for a sensor is formed on the outer peripheral surface of the plastic joint body. An electrofusion-type plastic pipe joint characterized in that the hole for the sensor is formed with a step having a small diameter on the bottom side, and the tip end portion is fitted into the hole for the sensor of the electrofusion-type plastic pipe joint. Is a sensor for an electric fusion type plastic pipe joint in which a tip is formed with a step having a small diameter. However, the electric fusion-bonded plastic pipe joint may be of a saddle type.

[Operation] In the plastic pipe joint and the sensor thereof according to the present invention described above, the sensor hole of the plastic pipe joint is formed with a step with a small diameter on the bottom side, and the tip of the sensor is formed with a step with a small diameter on the tip side. Therefore, when the sensor is put into the sensor hole of the plastic pipe fitting, those steps contact each other. Therefore, the contact pressure between the tip of the sensor and the bottom of the sensor hole of the plastic fitting is
Or the distance between them does not vary greatly.

[Embodiment] An embodiment of the plastic pipe joint and its sensor according to the present invention is shown in FIG. Figure 1 shows a plastic pipe fitting 1
FIG. 6 is a partial cross-sectional view showing a state in which a connector 3 having a thermocouple, which is a sensor, is attached.

The plastic pipe joint 1 includes a substantially cylindrical plastic joint body 10, a heating wire 20 wound and embedded in an inner peripheral surface portion of the plastic joint body 10, and a substantially columnar end portion of one end portion of the heating wire 20. 2 connector pins 21 connected to each
And a thermocouple hole 11 is formed on the outer peripheral surface of the plastic joint body 10.

One end of each of the two connector pins 21 connected to the heating wire 20 is embedded in the plastic joint body 10, and the other end projects from the outer peripheral surface of the plastic joint body 10. A cylindrical projection 16 is formed around the connector pin 21 on the outer peripheral surface of the plastic joint body 10 so as to be separated therefrom.

The thermocouple hole 11 is formed in the vicinity of the outside of the protruding portion 16 and has a step having a smaller diameter on the side surface at the bottom. That is, the thermocouple hole 11 has an upward (in FIG. 1) annular plane 12 on its side surface.

The connector 3 is a thermocouple 30 which is one of the temperature sensors.
And a connector bush 41 connected to the connector pin 21 of the plastic fitting 1, a guide 42 covering the connector bush 41, and a connector bush 41 covered by the guide 42.
And a holder 40 that integrates the thermocouple 30 with the thermocouple 30.

The connector bush 41 has a cylindrical portion that fits with the connector pin 21, and the guide 42 covers almost the entire outer circumference thereof. The outer circumference of the guide 42 that covers the cylindrical portion of the connector bush 41 has an outer diameter that fits with the inner circumference of the protruding portion 16 of the plastic pipe joint 1.

The thermocouple 30 consists of a right cylindrical thermocouple body 31 and this thermocouple body.
A reinforcing member 32 is provided to cover and reinforce except the tip end portion of 31. The tip of the reinforcing member 32 has a tapered taper shape, and the tip is a plane orthogonal to the axis, that is, the tip plane. Therefore, in the thermocouple 30, the tip end has a step with a small diameter at the tip.

The holder 40 is made of rubber and integrates the thermocouple 30 and the connector bush 41 covered with the guide 42 in a parallel positional relationship. The holder 40, which is located on the outer periphery of the guide 42 that covers the cylindrical portion of the connector bush 41, fits on the outer periphery of the protruding portion 16 of the plastic pipe joint 1.

When the connector 3 described above is attached to the plastic pipe joint 1, the connector pin 21 is fitted into the connector bush 41, and at the same time, the outer circumference of the guide 42 that covers the cylindrical portion of the connector bush 41 and the inner circumference of the protruding portion 16 further hold the holder 40. The inner circumference and the outer circumference of the protrusion 16 are fitted together. And thermocouple
30 is inserted into the thermocouple hole 11.

Here, even if the connector 3 is strongly pressed and attached to the plastic pipe joint 1, the most distal surface of the thermocouple 30, that is, the most distal surface of the thermocouple body 31, is not strongly pressed against the bottom surface of the thermocouple hole 11. Absent. This is because there is a step at the tip of the side surface of the thermocouple 30 and a step on the side surface of the thermocouple hole 11, and these steps are in contact with each other. That is, since the tipmost plane of the reinforcing member 32 of the thermocouple 30 and the annular plane 12 of the thermocouple hole 11 are in contact with each other, the reinforcing member 32 is provided from the tipmost surface of the thermocouple body 31.
Of the thermocouple hole 11 and the bottom surface of the thermocouple hole 11 to the annular flat surface 12 with accurate dimensions, the thermocouple 30 tip surface and the thermocouple hole 11 bottom surface Contact pressure does not vary.

Further, when the contact pressure between the most advanced surface of the thermocouple 30 and the bottom surface of the thermocouple hole 11 is high, the bottom surface of the thermocouple hole 11 is softened when a current is applied. It was conventional that the temperature was measured at a place close to the heating wire 20 that was embedded in the bottom surface and a higher measurement result was obtained. Therefore, the annular plane of the thermocouple hole 11 with which the most distal surface of the reinforcing member 32 of the thermocouple 30 contacts
It is necessary for 12 to be in a position and height where it does not sink, that is, does not soften.

When the plastic pipe joint 1 and the connector 3 having the thermocouple 30 of the present embodiment described above are used, the contact pressure between the most distal surface of the thermocouple 30 and the bottom surface of the thermocouple hole 11 of the plastic pipe joint 1 does not vary. Therefore, a good connection result can be obtained.

Although the plastic pipe joint 1 of the embodiment described above is a socket, it may be an elbow or a saddle for branching. The saddle is composed of a plastic saddle body having a substantially semi-cylindrical shape, a heating wire wound around and embedded in the inner peripheral surface of the plastic saddle body, one end of each heating wire is connected to one end and the other end is The plastic saddle body is formed with a connector pin projecting from the outer peripheral surface thereof, and a thermocouple hole similar to that of the plastic pipe joint 1 of the socket is formed.

The sensor of the embodiment described above is a temperature sensor, especially the thermocouple 30, but the sensor is not limited to the temperature sensor,
Alternatively, it is not limited to the thermocouple 30. The temperature sensor measures the temperature at the bottom of the temperature sensor hole of the plastic pipe joint as explained in the section of the prior art, and when this temperature reaches the set temperature, the heating wire of the plastic pipe joint is measured.
The purpose is to stop the current that was leading to 20. As a sensor to stop this current, when the heating wire 20 of the plastic fitting is energized, the bottom of the sensor hole formed in the plastic fitting rises, so it is a sensor that detects the displacement of this bottom. May be. That is, it may be a sensor that detects when the rising height of the bottom surface reaches a certain height. This sensor includes, for example, a sensor for detecting contact such as a micro switch, a sensor for detecting proximity such as a proximity switch, or a length measuring sensor such as an electronic dial gauge, a linear scale, and an electric micrometer. Even when using these sensors, the distance between the sensor hole bottom surface of the plastic pipe joint and the sensor's tip surface, the sensitive area, and the tactile area can be easily made to a precise dimension. The rising height of the bottom surface of the sensor hole of the plastic pipe joint can be accurately detected. Therefore, it is possible to accurately control the energization time of the heating wire 20 of the plastic pipe joint and obtain a good connection state.

[Effects of the Invention] As described above, when the plastic pipe joint and the sensor according to the present invention are used, the contact pressure between the tip of the sensor and the bottom surface of the sensor hole of the plastic pipe joint, or the distance between them, Since there is no variation, good connection results can be obtained.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view in which a thermocouple or the like is attached to the plastic pipe joint of this embodiment. FIG. 2 is a partial cross-sectional view in which a thermocouple or the like is attached to a conventional plastic pipe joint. 1 ... Plastic pipe joint, 2 ... Plastic pipe 3 ... Connector, 10 ... Plastic joint body 11,19 ... Hole for thermocouple, 12 ... Circular flat surface 16 ... Projection, 20 ... Heating wire, 21 ... Connector pin 30,39 … Thermocouple, 31… Thermocouple body, 32… Reinforcing material 40… Holder, 41… Connector bush 42… Guide, 43… Electric wire

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Ken Kato, 2 Daifuku, Kuwana City, Mie Prefecture, Kuwana Factory, Hitachi Metals Co., Ltd. (72) Yoichiro Kazama, 2 Daifuku, Kuwana City, Mie Prefecture, Kuwana Factory, Hitachi Metals Co., Ltd. Within

Claims (5)

[Scope of utility model registration request] Claim: What is claimed is: 1. A substantially cylindrical plastic joint main body, a heating wire wound around and embedded in an inner peripheral surface of the plastic joint main body, and one end of each heating wire is connected to one end and the other end is connected to the other end. A connector pin protruding from the outer peripheral surface of the plastic joint body, and an electrofusion plastic pipe joint having a sensor hole formed on the outer peripheral surface of the plastic joint body, wherein the sensor hole has a small diameter on the bottom side. An electric fusion-bonding type plastic pipe joint characterized by being formed into a step. 2. A plastic saddle body having a substantially semi-cylindrical shape, a heating wire wound around and embedded in an inner peripheral surface portion of the plastic saddle body, and one end of each heating wire is connected to one end and the other end thereof is connected. A connector pin projecting from the outer peripheral surface of the plastic saddle body, and an electric fusion-bonded plastic pipe joint having a sensor hole formed on the outer peripheral surface of the plastic saddle body, wherein the sensor hole has a bottom side. An electro-fusion type plastic pipe joint characterized by being formed in a step with a small diameter. 3. An electrofusion-type plastic pipe joint in which the tip portion is stepped so that the tip side has a small diameter so as to fit into the sensor hole of the electrofusion-type plastic pipe joint according to claim 1 or 2. sensor. 4. The electrofusion-type plastic pipe joint according to claim 1, wherein the sensor hole is a temperature sensor hole. 5. The electric fusion-bonding plastic pipe joint according to claim 4, wherein the tip end portion is formed with a step having a small diameter on the tip side so as to fit in the temperature sensor hole. Temperature sensor.