JPS62297076A - Gas combustion type piston drive - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Application of the Invention] The present invention relates to a device that generates high pressure to drive a piston in order to instantaneously operate the piston, such as a nailer or tacker. It's about Z.

[Background of the invention]

Conventional equipment such as nailers and tackers generally use high-pressure air to perform their work. However, these devices are operated by connecting a hose between the compressor and the device.
[Object of the Invention] The purpose of the present invention is to eliminate the above-mentioned drawbacks of the prior art and also to enable the same work as before without using an expensive compressor. be.

[Summary of the invention]

The present invention burns a fuel mixture such as liquefied gas in a closed space and uses the expansion force of the combustion gas to drive a piston, but generally the combustion speed of the fuel mixture is determined by the internal combustion rate. Focusing on the fact that a turbulent flow is faster than a single flow, and that when an object is placed in the flow, vortices are generated downstream of the object, resulting in turbulent flow, the turbulence is strengthened to increase the burning speed of the fuel mixture The combustion chamber was designed to increase the combustion gas, expand the combustion gas at high speed, generate high pressure, and drive the piston at high speed.

[Embodiments of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a gas combustion type piston drive device according to the present invention will be described with reference to FIGS. 1, 2, 3, 4, and 5, with reference to drawings of, for example, a nail gun.

In the figure, 1 is a housing having an opening 1a at the end, 2 is a cylinder fixed to the opening la side of the housing 1, 3 is a piston that can slide inside the cylinder 2, and 4 is the opposite side of the cylinder 2 to the housing l. It is a guide fixed to the side. Inside the guide 4, a rod 6 fixed to the piston 3 slides so as to drive a nail 5, and a nail feeder 7 for inserting the nail 5 into the guide 4 is attached to the side of the guide 4.

The housing 1 includes a fuel injector 8 for injecting liquefied gas such as propane or butane, an air injector 9 for injecting air, and 2 valves that open and close in synchronization with the air injector 9, using piezoelectric elements, etc. Spark voltage generator 11, spark voltage generator] The spark plug 12 generates a spark by the high voltage generated in 1 and ignites the fuel mixture, and the space B where the fuel mixture passes and the flame propagates after ignition is almost the entire surface. Lattice 11 scattered in
4-14d1 Passages b, lf near both ends of housing 1
The housing 1 has a circulation path copper connected to the housing 1 and a part of the housing 1 partitioned off by a partition wall 17. The passage [6] has a nozzle [9] which communicates with a fuel injector 8 and injects fuel, and a mixing pipe 20 with a gap provided around the nozzle 19.

There is an O-ring 21 on the sliding part of the piston 3 and the cylinder 2.
The space closed by the housing 1, cylinder 2, and piston 3 forms the combustion chamber η, and the combustion chamber n
are divided into 22a to 22e by grids 14a to 14d.

The ignition blur is located on the closed end side of the housing 1, and grids 141 to 14d are provided between the ignition blur and the opening ta of the housing 1. The grate 14d closest to the housing opening [a] prevents the piston 3 from moving from the cylinder 2 into the housing 1. The lattice IJa to 14d is a flat plate with a space L3 on the entire surface as shown in FIG.
Alternatively, as shown in FIG. 4, a mesh is formed using wire rods, and in both cases, spaces B and bars Z are scattered over the entire surface of the grid.

In the piston sliding part 2a of the cylinder 2, 24 is a piston stop part (Fig. 2) located at the end on the housing 1 side, and has a somewhat larger diameter than the other piston sliding parts 2a, so that the piston 3 is on the housing 1 side. When the OII song 1 moves to the piston stop portion 24, the elastic force of the OII song 1 causes the piston 3 to stop on the housing 1 side.

An elastic body 22 is attached to the guide 4 side of the cylinder 2. The cylinder 2 also has an intake/exhaust port through which the air surrounded by the housing 1, cylinder 2, and piston 3 communicates with outside air when the piston 3 moves and contacts the elastic body n; It has an exhaust port l.

A is a regulator, attached to the outer wall of the exhaust port n of cylinder 2,
An adjustment port part that changes the flow path resistance by changing the cross-sectional area of the exhaust port by operating the regulator 28 in directions 29a, 29I), a valve blower 31 that communicates with this adjustment port 30, and an exhaust port from inside the cylinder 2. A one-way valve 3 that allows gas to flow out through the regulating port and the pulp controller 31 and prevents gas from flowing into the cylinder 2 from the outside.
It has 2.

Next, the operation of this nail gun will be explained. First, the piston 3 is stopped at the piston stop 24 as shown in FIG. Therefore, air is injected from the air injector 9 and the valve 10
is opened to exhaust the air in the combustion chamber 22 and fill the combustion chamber n with fresh air, and then the air injector 9 and valve 10 are closed. Next, when fuel is injected from the fuel injector 8 through the nozzle 9, air in the passage flows toward the combustion chamber 22a due to the jet of fuel coming out from the nozzle 9.
While passing through, it becomes a mixture of air and fuel and enters the combustion chamber η.

When the air in the combustion chamber 22d passes through the passage, it enters the combustion chamber 22a through the circulation passage fat and the passage η, becomes a fuel mixture, passes through the space n of each grid 15 to 14d, and enters the combustion chamber. The entire n is filled with fuel mixture. In this state, the spark voltage generator 11 is operated and the ignition plug 12 ignites the fuel mixture. Combustion gas expands due to combustion within the combustion chamber 22a, and the unburned gas that has not yet been combusted is pushed through the spaces n of each grid Ma to 14d to the combustion chamber 22.
The unburned gas of a flows into the combustion chamber 22b, and
The unburned gas flows into the combustion chamber 22C, and the unburned gas flows in the direction of the piston 3 one after another. The crosspiece 23 becomes an obstacle to the flow of the unburned gas that has passed through the space-time 13, and a vortex is generated downstream of the crosspiece, resulting in a turbulent flow. The flame in the combustion chamber 22a is a laminar premixed flame with a slow combustion speed, but when the flame propagates and passes through the space n of the grid 14a, turbulence causes the combustion chamber 2
The flame in 2I) becomes a turbulent premixed flame and the combustion speed increases. As the combustion speed increases, the expansion speed of the combustion gas increases, and the flow speed of unburned gas flowing from the combustion chamber 22b into the combustion chamber 22C increases, so that unburned gas is generated downstream of the crosspiece 23, which is an obstacle to the grid 14b. The vortex becomes even stronger, creating strong turbulence. When the flame propagates into the combustion chamber 22C due to this strong turbulence, the combustion speed becomes even faster. In this way, each time the flame passes through the grid, the combustion speed increases at an accelerated rate, and the increase in combustion speed increases the expansion speed of the combustion gas, causing the pressure inside the housing to rise and become high pressure. Due to this high pressure, the piston 3 is pushed out from the piston stop 24 toward the guide 4 against the elastic force of the O-ring 21, enters the driving stroke, and drives the nail 5 into the workpiece such as wood as shown in FIG. .

When the piston 3 is driven and moves toward the guide 4, the air in the compression chamber 34 surrounded by the piston 3, cylinder 2, guide 4, and elastic body δ' is discharged to the atmosphere from the intake and exhaust port 26, and Due to the action of the nearby grid 14d, a strong turbulence is generated in the combustion chamber surrounded by the piston 3, cylinder 2, and grid 14d, and as the flame propagates, the combustion speed further increases and strong pressure is generated, causing the rod 6 to reduce the area of the nail 5. generates the strong force necessary to drive the large head of the The regulator path is for adjusting the driving force of the nail 5 by adjusting the pressure in the combustion chamber 22.
By moving to the side, the pressure inside the cylinder 2 can be released. The driving force of the nail 5 becomes maximum when the adjuster 28 is moved in the direction of 29a and the adjustment port ( ) is closed.
When moving in the direction b and opening the adjustment port 30, the size becomes smaller.

When the piston 3 is driven and passes through the intake/exhaust port 26, the piston 3 collides with the elastic body 25, and the high-temperature, high-pressure gas in the combustion chamber n is exhausted into the atmosphere from the intake/exhaust port 26, and the piston 3 compresses room temperature air. do. After that, the temperature inside the combustion chamber 22 rapidly decreases and the combustion chamber 22 becomes a vacuum, and the piston 3 is pushed up by the elastic force of the elastic body 25 and the compression force of the compression chamber 34 and moves from the intake/exhaust position to the housing. Since the housing 1 side of the piston 3 is under vacuum and the guide 4 side of the piston 3 is at atmospheric pressure, the differential pressure causes the piston 3 to return to the piston stop portion 24 and stop when it comes into contact with the grid 14d, where it is held by the elastic force of the OII song 1. Return to initial state. The regulator 28 is closed when the pressure inside the cylinder 2 drops below atmospheric pressure due to the action of a one-way valve, so it is closed during the return stroke of the piston 3.

A modification of the present invention will be explained using FIG. 6 and FIG. 1. In the figure, reference numeral 23 denotes a cross section, and its cross-sectional shape may be any shape such as circular, square, or triangular, and the longitudinal shape of the crosspiece 23 may be any shape such as a straight line or curve. That's fine. The crosspieces 23 are interspersed between the spark plug 12 in the housing 1 and the opening lα of the housing 1. The size of the opening 1a in the housing 1 is smaller than the diameter of the piston 3 to prevent the piston 3 from moving toward the housing 1. After the fuel mixture is ignited by the spark plug 12, the combustion gas expands and unburned gas flows toward the piston 3, causing the flame to propagate toward the piston 3 due to the vortex generated downstream of the crosspiece in the housing 1. The combustion speed increases at an accelerated rate, generating strong pressure and driving the piston 3.

As a variant, although not shown, the exhaust port 27 of the sealing 2 and the regulator 28 may be arranged in the wall of the housing l.

〔Effect of the invention〕

According to the present invention, it is possible to generate strong pressure and drive the piston by burning the fuel mixture at high speed, so there is no need for other power sources such as an expensive compressor.
It is possible to provide an inexpensive piston drive device with improved portability and no need for hoses or cords.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional side view of a nailing machine showing an embodiment of the gas combustion type piston MA < moving device according to the present invention, and FIG. FIGS. 3 and 4 are front views of the barrier, FIG. 5 is a sectional view taken along line I-I in FIG. 1, and FIG. 6 is a housing showing a modified example of the barrier. A vertical side view, FIG. 1 is a sectional view taken along the line II--II in FIG. 6. In the figure, 1 is the housing, lcL is the opening, 2 is the cylinder, 3 is the piston, 8 is the fuel injector, 9 is the air injector, 10 is the valve, C is the spark plug, r) is the space, and k
is a turbulence generator (obstruction), 6, phase is a passage, 18 is a circulation path, uniform is a nozzle, 20 is a mixing pipe, 22 is a combustion chamber, n is an exhaust port, 28 is a regulator, 3o is a control port be. Name of patent applicant: Hitachi Koki Co., Ltd.

Claims (1)

[Claims] 1. A housing having an opening at one end, and a piston sliding in a cylinder adjacent to the opening of the housing;
An injector for injecting fuel into the housing, a means for exchanging air in the housing, an ignition device in the housing, and obstacles and passage gaps interspersed in the housing to prevent unburned gas after ignition. and a turbulence generating device that generates a vortex in the flow of fuel, and when the mixture of fuel and air is ignited, flame propagates from the ignition source in the housing and turbulence generated by obstacles is also included. A gas combustion type piston drive device, characterized in that the turbulent flow of combustion gas causes the combustion speed to rise and accelerate to generate high pressure, and the piston is driven by the high pressure. 2. Claim 1, further comprising: an ignition device having an ignition source disposed near a closed portion of the housing; and an obstacle constituting a turbulence generating device between the ignition source and the opening of the housing.
Gas-fired piston drive device as described in . 3. The gas combustion type piston drive device according to claim 1, wherein the obstacles constituting the turbulence generating device exist in multiple stages with respect to the flow of unburned gas after ignition. 4. A passage communicating with the opening of the housing, a passage communicating with the closed part of the housing, a circulation passage connecting both passages, a passage disposed in one of the passages, having a gap around the periphery, and a passage in the center. 2. A gas combustion type piston drive device according to claim 1, comprising a fuel and air mixing device comprising a mixing tube having a nozzle for injecting fuel from the fuel tank. 5. An exhaust port bored in the wall of the housing or the cylinder, and an adjustment section that communicates the exhaust port with the atmosphere and can freely vary the flow path resistance, and adjusts the pressure inside the housing and the cylinder. The gas combustion type piston drive device according to claim 1, further comprising an adjuster for adjusting piston drive force.