JPH0151310B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a recoilless urethane hammer.

A hollow chamber is provided inside the striking head of the hammer, and a granular or block-shaped inertial material is movably stored inside the hollow chamber, and the movement of this inertial material suppresses the recoil that occurs when striking. Such hammers are already known as recoilless hammers. This type of recoilless hammer produces a stronger striking force and at the same time suppresses the recoil transmitted to the worker's hands, which has the advantage of reducing worker fatigue, and is widely used in various workplaces. has been done.

On the other hand, hammers in which the striking surface of the striking head of the hammer is made of or coated with an elastic material such as rubber or synthetic resin are widely used in the wood industry, sheet metal industry, etc. because they do not damage the striking surface. has been done. This type of hammer also has the advantage of not producing sparks when striking metal parts, making it extremely useful for fire protection.

Hammers that have both the recoilless effect and the fact that they do not damage the surface being struck are known.
Patent Application Publication No. 9198 of 1975 discloses a device consisting of a skeletal member of a handle called a skeletal spline member, and a cylindrical head member attached to one end of the handle and having a lead bullet sealed inside. discloses a hammer in which the hammer is made into a hammer shape by surrounding it with a rubber-based polymer, and as a manufacturing method thereof, a pin for positioning the skeletal spline member and the skeletal head member is provided. A method is described in which the mold is placed in the mold through the mold, the molds are then assembled and the outer packaging material is injected. In this method, the spline member and the head member that form the skeleton must be made in advance from metal materials such as brass, and the head member must be filled with an inertial material such as lead and when capping both ends. Great care must be taken to ensure that the interior is completely airtight. Also, when placing the skeletal member in a specific mold within the mold,
A considerable amount of effort and care is required to match the pins of the mold and the holes that receive them in the skeleton member, and after the mold is removed, small holes remain in the outer envelope where the pins were removed.

An object of the present invention is to provide an efficient, low-cost recoilless urethane hammer that can withstand long-term use without damaging the striking surface, removing the striking head, or breaking the handle. The present invention provides a method for manufacturing.

The present invention provides a hammer in which a striking head and a handle are integrally molded from urethane resin, in which a hollow chamber is provided inside the striking head, an inertial material is movably housed therein, and a core is inserted into the center of the handle. In this method of manufacturing a recoilless urethane hammer, that is, injecting urethane resin into a mold and molding the hammer, a preformed brazing member is placed at a predetermined position in the mold, and the urethane resin is injected into a mold. After the resin hardens, the solder member is melted and removed to form a hollow chamber inside the striking head and a passage in the center of the handle that communicates with the hollow chamber from one end to the other, and the inertial material is introduced into the hollow chamber through the passage. The present invention relates to a method for manufacturing a recoilless urethane hammer, characterized in that the hammer is inserted into the passageway, and a core is inserted into the passageway to close the end thereof.

The most preferred embodiment of the method for manufacturing a recoilless urethane hammer according to the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an example of a recoilless urethane hammer according to the present invention, in which a striking head 2 is integrally molded with urethane resin at the tip of a handle 1, and a hollow chamber 3 is formed inside the striking head 2. Iron sand 4 is movably housed therein as an inertial body. A core 5 is embedded in the longitudinal direction of the center of the handle 1.

FIG. 2 shows the state when the two-sided molding molds 10 and 11 are opened, and the hammer handle 1 and striking head 2 are formed on the inner surfaces of each mold by the urethane resin injected from the injection port 12. Cavities 15, 16 are provided for integral molding. Mold 1
Pin 18 for positioning when combining 0 and 11
and a suitable number of receiving holes 19 on each inner surface,
It will be set up. A brazing member 20 for forming a hollow chamber 3 in the striking head 2 and a passage communicating with the hollow chamber 3 from the end of the handle 1 is attached to the molding die 1.
It is located within 0. The solder member 20 is pre-molded with a wax selected from waxes that melt between 60 degrees Celsius and 110 degrees Celsius, and consists of a head and a rod-shaped handle. It is suspended in the cavities 15, 16 of the molds 10, 11 by means as shown in FIG. That is, mold 1
When combining both sides of No. 0 and No. 11 and fitting the upper lid 25, the tip of the rod-shaped handle of the solder member is passed through the hole in the center of the upper lid 25 and protrudes upward, A pin 26 is inserted into the drilled hole, locked, and suspended. The upper lid 25 has openings 27, 2 for injecting the urethane resin solution.
It has 7.

Next, the manufacturing process according to the present invention will be explained. First, as shown in FIG. 1, a brazing member is locked inside the molding die, the two molds 10 and 11 are combined, and a urethane resin solution is injected from the injection port 12 at the top.
After solidifying the urethane resin (primary vulcanization), it is demolded and heated for aging (secondary vulcanization). Due to this heating, the wax member 20 is softened and melted, so that it is actively flowed out from the passage in the center of the handle 1, thereby forming a hollow chamber 3 in the striking head and a passage in the center of the handle communicating with the hollow chamber 3. can be formed. After this dewaxing treatment, a suitable amount of iron sand 4 as an inertial material is put into the hollow chamber 3 in the striking head through a passage formed in the center of the handle 1, a metal rod is inserted into the passage, and a core 5 is inserted. Form. The end of the passage is sealed by injecting a urethane resin solution. Note that the tip of the metal rod core 5 may reach the opposing wall surface of the hollow chamber 3 within the striking head.

In the present invention, the urethane resin is preferably made to have a hardness of Shore A of 80 degrees or more by blending a curing agent, and is solidified (primary vulcanization) between 30 degrees Celsius and 100 degrees Celsius.
However, it is possible to use an appropriate selection from those that are aged (secondary vulcanization) between 30 degrees Celsius and 110 degrees Celsius. On the other hand, the solder member 20 is molded with a wax that softens and melts at a temperature higher than the solidification (primary vulcanization) point of the selected urethane resin. For example, 30 degrees Celsius
When using a urethane resin that solidifies at 50 degrees Celsius (primary vulcanization) and matures at 50 degrees Celsius to 80 degrees Celsius (secondary vulcanization), the solder member 20 is formed using a wax with a melting point of 60 degrees Celsius. do. In addition, when using thermosetting urethane resin that solidifies at 80 to 100 degrees Celsius and matures at 100 to 110 degrees Celsius,
A wax member 20 is formed.

5 to 7 show other embodiments, and in FIG. 5, the metal disks 30, 31 are connected to the metal rod 32.
6 shows a support member which is embedded in a solder member to form a hollow chamber within the hammer striking head and extends from the distal end of the handle as shown in FIG. The member for forming the passage communicating with the hollow chamber in the striking head is formed of a metal pipe 35 instead of wax.
In this case, the wax of the member for forming the hollow chamber 3 in the striking head, which is melted in the dewaxing step, flows out from the distal end of the handle through the hollow chamber in the metal pipe 35, as shown in FIG. As shown, the metal pipe 35 itself remains in the center of the handle 1 and forms a core. Thereafter, iron sand 4 as an inertial material is introduced into the hollow chamber 3 in the striking head from the hollow part of the metal pipe 35, and the hollow part of the metal pipe 35 is filled and closed with urethane resin. This metal pipe core 35 is extremely effective when used with a large hammer. metal rod 3
The metal discs 30, 31 supported by 2 are
It remains in the hollow chamber 3 within the striking head and protects both side walls within said hollow chamber 3 from wear due to movement of inertial material.

Although the preferred embodiments of the present invention have been described above, the present invention can be implemented with various changes based on the constituent elements described in the claims.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a recoilless urethane hammer according to the present invention, FIG. 2 is a perspective view showing a state in which both sides of a molding die for implementing the present invention are opened, and FIG. FIG. 4 is a sectional view taken along the line of FIG. 3, FIG. 5 is a perspective view of the support member, and FIG. FIG. 7 is a perspective view showing another embodiment of the forming member, and FIG. 7 is a longitudinal sectional view showing another embodiment of the recoilless urethane hammer of the present invention. 1...Handle, 2...Blowing head, 3...Hollow chamber, 4...
...Iron sand, 5... Core, 10, 11... Molding mold, 1
2...Inlet, 15, 16...Vacancy, 20...Brazing member, 25...Top lid, 26...Pin, 30,3
1...Metal disk, 32...Metal rod, 35...Metal pipe.

Claims (1)

[Claims] 1. In a method of injecting urethane resin into a mold and molding a hammer, a pre-formed brazing member is placed at a predetermined position in the mold,
After the urethane resin has hardened, the solder member is melted and removed to form a hollow chamber inside the striking head and a passage in the center of the handle that communicates with the hollow chamber from the end, and the inertial material is introduced into the hollow chamber through the passage. A method for manufacturing a recoilless urethane hammer, characterized in that the core is introduced into the passageway and the end thereof is closed. 2. A supporting member consisting of a metal disk supported by a metal rod is embedded in the head of the waxing member, and after dewaxing treatment,
The method for manufacturing a recoilless urethane hammer according to claim 1, wherein both side walls of the hollow chamber in the striking head are protected by the supporting member. 3. The method for manufacturing a recoilless urethane hammer according to claim 1, wherein the handle of the brazing member is formed of a metal pipe, and after dewaxing treatment, the core of the handle of the hammer is formed. 4. Claim 1, which is selected from urethane resins that are solidified at temperatures between 30 degrees Celsius and 100 degrees Celsius and aged at temperatures between 30 degrees Celsius and 110 degrees Celsius.
A method for manufacturing a recoilless urethane hammer as described in . 5. The method for manufacturing a recoilless urethane hammer according to claim 1, wherein the brazing member is formed with a wax selected from waxes, which is melted at a temperature between 60 degrees Celsius and 110 degrees Celsius.