JPS5830199Y2 - Vacuum furnace temperature measuring device - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a vacuum furnace temperature measuring device.

Temperature control in a vacuum heat treatment furnace is usually carried out by measuring the temperature with a thermocouple. Conventionally, this thermocouple is fixedly placed outside the working area of the furnace, and when the workpiece is taken in and out of the furnace, it is connected to the workpiece. to avoid interference.

However, in recent years, the tolerance standards for heat treatment temperatures have become stricter. For example, the temperature distribution during heating may vary within ±5°C from the temperature indicated by the control thermometer throughout the working area where the workpiece is placed. This requirement has become impossible to meet if the thermocouple measurement point is located outside the working area.

The present invention uses a hollow double-rod type piston rod and cylinder with a hole so that the thermocouple passes through the inside, and when the piston rod is advanced into the furnace, the thermocouple attached to the rod is activated. The tip is located within the working area,
The tip of the thermoelectric lamp is positioned outside the working area when the rod is retracted toward the outside of the furnace.One embodiment of the thermoelectric lamp will be described with reference to the drawings.

In the drawings, a cylinder 1 is provided outside the vacuum furnace main body 2, is directly attached to a mounting flange 3, and is gas-sealed.

Reference numeral 4 denotes a piston rod, which is provided so as to protrude from the inside of the cylinder 1 in the direction inside the furnace and toward the outside of the furnace, so that it can reciprocate and slide in the direction inside the furnace and the direction outside the furnace, and has a hollow portion 5 inside. It consists of a double rod type.

A thermocouple 6 is of a closed type with a protection tube, and is attached to a flange 7 of the piston rod 4 by passing through the hollow portion 5 of the piston rod 4, and is gas-sealed.

When the piston rod 4 enters into the furnace, the thermocouple 6's tip 8 is located within the working area 9 of the vacuum furnace, and the rod 4 is retracted toward the outside of the furnace. It is attached to the rod 4 so that the tip 8 is located outside the working area 9 when the rod 4 is turned.

That is, as the piston rod 4 moves back and forth, the tip 8 of the thermocouple 6 moves in and out of the working area 9, and the thermocouple 6 shown by the solid line in FIG. state, whose stroke is denoted by a.

In addition, in the drawing, 10 is a heat shielding plate, 11 is a stopper for positioning the thermoelectric lamp, 12 is a cooling tube, 13 is a heater, and 14 is a work support.

In the vacuum furnace temperature measurement device configured in this way,
Inert compressed gas such as nitrogen gas (at a pressure of 1
5-9 kg/cm2) is used as the working fluid and the piston rod is reciprocated to move the tip 8 of the thermocouple 6 into and out of the working area 9.

That is, when measuring the temperature inside the furnace, the piston rod 4 is moved forward to position the tip 8 of the thermocouple 6 within the working area 9, and when the workpiece is taken in and out, the tip 8 of the thermocouple 6 is placed so that it does not interfere. Then, the piston rod 4 is retracted so that the tip 8 of the thermocouple 6 is located outside the working area 9.

As mentioned above, the vacuum furnace temperature measuring device of the present invention is designed so that the tip of the thermocouple can be moved in and out of the working area, so when measuring the temperature inside the furnace, the tip of the thermocouple can be positioned within the working area. This makes it possible to accurately measure temperature, and since the tip of the thermocouple is positioned outside the working area when loading and unloading the workpiece, interference with the workpiece can be avoided, making it extremely convenient.

In addition, the drive mechanism for taking in and out the thermocouple consists of a combination of a cylinder and a double-rod type hollow piston rod, the thermocouple is attached to the rod by passing through the hollow part of the rod, and the cylinder is directly connected to the furnace body. Since it is installed,
The thermocouple can be moved in and out of the working area smoothly, vacuum sealing between the furnace and the furnace is easy, space is required, and the thermocouple can be easily replaced.

[Brief explanation of the drawing]

The drawings show one embodiment of the vacuum furnace temperature measuring device of the present invention, and FIG. 1 is a longitudinal sectional front view of the device, and FIG. 2 is a partial cross-section of the device shown in FIG. 1 installed in a vacuum heat treatment furnace. It is a diagram. 1...Cylinder, 2...Vacuum furnace main body,
4... Piston rod, 5... Hollow part, 6... Thermocouple, 8... Tip, 9...
...Working area, a...Movement range.

Claims (1)

[Scope of utility model registration request] A cylinder attached to the outside of the vacuum furnace body, and a double-rod hollow piston that protrudes from inside the cylinder to the inside and outside of the furnace and slides back and forth in the inside and outside of the furnace. It consists of a rod, and a thermoelectric lamp that penetrates the hollow part of the piston rod and is attached to the piston rod so as to make the same reciprocating motion as the piston rod,
Further, the tip of the thermocouple is located within the working area of the vacuum furnace when the piston rod is advanced into the furnace, and the tip of the thermocouple is located within the working area of the vacuum furnace when the piston rod is withdrawn toward the outside of the furnace. A vacuum furnace temperature measuring device, characterized in that the piston rod is attached to the piston rod so that the tip thereof is located outside the working area.