JPH0225600Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a coating extrusion device for a welding rod coating machine, and particularly to an extrusion device having an extrusion piston head with excellent durability.

(Prior art) When manufacturing coated welding rods, the coating machine used to coat the periphery of the core wire with a coating material usually has a third coating machine.
It is configured as shown in the figure. That is, the coating material 18 is filled into the coating material cylinder 11 equipped with the die head 17 on the tip side, and the piston rod 15 reciprocated by the hydraulic cylinder 19 is inserted into the cylinder 11 to extrude the coating material 18 at the same time. The coating work is performed by supplying the core wire by a wire feeder 21 through a guide pipe 20 provided in the die head 17, and ejecting the core wire and coating material from the die head.

Therefore, it is desired that the piston portion that reciprocates within the coating cylinder has sufficient airtightness and as high durability as possible. Poor durability means that the piston sliding part (head part) must be replaced more frequently, which is disadvantageous in terms of productivity, especially in the continuous manufacturing method of coated welding rods that has been introduced in recent years. .

Hitherto, there have been few proposals regarding this extrusion piston, and only one known is Japanese Patent Publication No. 39-9469. However, this is not about the durability of the piston either.

FIG. 2 shows a structure commonly used for this type of piston. In the figure, 11 is a coating cylinder, 12 is a piston rod 1 with a collar 13 in between.
5 is a cast iron piston ring, 14 is an adapter for holding the ring 12, and 16 is a T-shaped piston head for fixing these members.

(Problems to be Solved by the Invention) In the above-mentioned existing extrusion piston, slight wear of the piston ring impedes the coating extrusion operation, so it is necessary to immediately replace it. For example, cylinder inner diameter intersection is 180+
In the case of 3/100, the piston ring outer diameter intersection is 180 - 2/100, and if this piston ring outer diameter wears down to 179 mm, problems such as leakage of the coating material will occur, so replacement is required. Normally, this replacement frequency is once/100t, which is insufficient in terms of durability.

The present invention aims to solve these problems and dramatically increase the durability of the piston.

(Means and actions for solving the problems) The configuration of the extrusion device of the present invention for achieving the above object is as follows. That is, in a coating material extrusion device for a welding rod coating machine that has a cylinder filled with a coating material and an extrusion piston that is inserted and slid into the cylinder, a piston ring is attached to the rod tip of the piston, and a piston ring is attached to the piston ring. , a collar with an O-ring smaller in diameter than the ring and provided on both sides in the axial direction is attached, and a plurality of V-shaped packings are attached so as to contact the side surface of the piston ring and the outer circumferential surface of the collar, with the pointed direction pointing toward the piston. A coating material extrusion device for a welding rod coating machine, characterized in that a piston head with a T-shaped cross section that is mounted so as to face opposite to the pressing direction and further presses the V-packet is screwed onto the tip of the rod. It is.

In the present invention, the V-packet is held and clamped by the piston ring, collar, and piston head, and depending on the orientation of the packing, the packing expands when the piston rod moves forward and contracts when the piston rod moves backward. This reduces dynamic resistance and reduces wear.

(Example) The present invention will be described below based on an example shown in the drawings.

As shown in FIG. 1, the distal end side of the piston rod 8, on which each member constituting the sliding portion of the piston relative to the coating cylinder is attached, has a step formed along its outer periphery over a certain length. First, an adapter 7 having a diameter larger than that of the rod is fitted to the stepped portion of the cylinder rod 8, and a cast iron piston ring 6 having a slightly larger diameter than the adapter 7 is engaged in a stepped state, and the ring 6 is engaged with the adapter 7 in a stepped manner. For O-ring 5a
A collar 4 which is in contact through the ring 6 and has a smaller diameter than the ring 6
A plurality of (four in the figure) V gaskets 3 are provided so as to contact the outside of the collar 4 and the ring 6, and the collar 4 and O-ring 5b are attached to press these against the piston rod 8. A T-shaped piston head 2 which contacts the V-packing 3 through the cylinder rod 8 is screwed into the cylinder rod 8.

The plurality of V gaskets 3 have the same outer diameter as the piston ring 6, and are preferably made of cloth-filled leather (tanned leather) or cloth-filled hard rubber.
As shown in the figure, it is held between a V-shaped groove formed on the contact surface of the piston ring 6 and a V-shaped protrusion formed inside the outer diameter of the piston head 2. Therefore, the V-packet 3 is also set so that its sharp side is opposite to the coating cylinder 1, that is, in the opposite direction to the piston pressing direction.

The adapter 7 is used to hold the ring 6 and functions like a washer. In addition, the piston ring 6 receives the V-packet 3 and also
performs an auxiliary function. Color 4 is V Packkin 3
It is necessary for receiving the inner periphery of the O-rings 5a and 5b and for attaching the O-rings 5a and 5b. The O-ring serves to prevent the coating material from seeping into the threaded fitting part. Furthermore, the piston head 2 is essential for fixing and pressing these members, and is made of a wear-resistant material with a Cr-plated surface. Note that among these, the adapter 7 may be omitted depending on the case.

The V-packet 3 plays an important role in the present invention, and when the piston is inserted into the coating cylinder 1 and reciprocates, it exhibits the most suitable function as a piston sliding part. That is, in the case of forward movement (pressing stroke), the V-pack 3 slides on the inner wall of the cylinder 1 and tends to expand in the direction of its V-shape, thereby achieving good packing action. Further, in the case of backward movement (backward stroke), the V-packet 3 tends to contract, contrary to the forward movement, and the return resistance is small.

(Effects of the invention) According to the pressing device of the invention, the durability of the piston sliding portion is significantly improved compared to the conventional one. For example, according to experiments conducted by the present inventors, with conventional piston rings, the ring had to be replaced after 100 tons, but with the present invention,
At 300t, the V gasket was replaced, and the piston ring was
It was replaced at 400t. Generally speaking, this invention is based on the conventional 3~
It was found to be 7 times more durable. This is because the V-packet of the present invention has very little wear.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of the present invention, FIG. 2 is a sectional view showing a conventional piston structure, and FIG. 3 is a plan view showing an outline of a coating coating machine. 1... Coating cylinder, 2... Piston head, 3...
V gasket, 4...Collar, 5...O ring, 6...Piston ring, 7...Adapter, 8...Piston rod.

Claims (1)

[Claims for Utility Model Registration] A coating material extrusion device for a welding rod coating machine that has a cylinder filled with a coating material and an extrusion piston inserted and slid into the cylinder, wherein a piston ring is attached to the rod tip of the piston. A collar having a smaller diameter than the ring and provided with O-rings on both sides in the axial direction is attached to the piston ring, and a plurality of V-shaped packings are attached to the piston ring so as to be in contact with the side surface of the piston ring and the outer peripheral surface of the collar. A welding rod coating characterized in that the piston head is mounted so that its pointed direction faces opposite to the piston pressing direction, and the piston head with a T-shaped cross section that presses the V-packet is screwed onto the tip of the rod. Machine coating extrusion equipment.