JPS6237964Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vent valve in an oil tank of a manual or foot pump.

Normally, in this type of hydraulic pump, the liquid level in the oil tank rises and falls during its operation, which creates negative pressure in the air and obstructs the suction inside the pump, or when the pressure oil backflows. The air was compressed and the pressure increased, sometimes even crushing the oil tanks. For this reason, conventional methods have been used to supply air into the oil tank by installing a special plug or vent valve for replenishing the hydraulic oil, and by relaxing the valve, air is fed in and the pump is activated. With this, the operation must be performed every time work begins, and the plug or vent valve must be tightened at the end of work to prevent hydraulic oil from overflowing during transportation. Moreover, this strictness was often forgotten.

The present invention provides a configuration in which air can be supplied in conjunction with operation of the operating stick during operation. To explain the drawings in detail, Fig. 1 shows a longitudinal section of the oil tank and the vicinity of the pump body of the foot-operated hydraulic pump according to the present invention, and Fig. 2 shows a general plan view thereof, showing the oil tank 1. The pump main body 2 is oil-tightly screwed onto the left end, and an operating rod 4 that swings around the pin 3 via a pin 3 is disposed on the upper part of the pump main body 2. It is locked by an operation stick stopper 5 provided at the.

A pin 6 passes through the left end of the operating rod 4, and springs 7 and 7' are suspended from both sides of the operating rod 4, and the lower ends of the pins 6 are fixed to the bed 8. An adjustment screw 9 is screwed into a position between pins 3 and 6 of the operation rod 4, and adjusts the opening degree of the operation rod during foot operation. A pin 10 is passed through the pin 3 slightly behind the pin 3, and a plunger 11 is suspended from the center of the pin 10 in an oil-tight manner so as to be able to move up and down.
Inside, there are two stages for high and low pressure.

A vent valve body 12 made of an adjustment bolt is screwed into the center of the operating rod 4, and a projection 13 on the upper surface of the oil tank 1 corresponding to the vent valve body 12 is made of an elastic body having a vent hole in the center. A vent valve seat 14 is fitted and communicates with a vent hole 15 passing through the center of the protrusion 13. A plug 16 for replenishing hydraulic oil is oil-tightly screwed onto the right end of the upper surface of the oil tank, and the tip of the plug 16 is formed flat in order to know the amount of oil stored when the plug 16 is pulled out. Note that 17 indicates an oil feed port, and 18 indicates a pedal for an open valve.

With the above configuration, the following operations are performed in the present invention. When the operation stick holder 5 is released, the operation stick 4
is swung about the pin 3 to the position shown by the two-dot chain line by the pulling force of the springs 7, 7' (this position is adjusted by the adjustment screw 9). This operation causes the plunger 11 to be pulled up, and the hydraulic oil in the oil tank 1 to be sucked into the pump body 2. At this time, the valve head of the vent valve body 12 is pulled away from the vent valve seat 14 on the upper surface of the oil tank, so that air is automatically sucked into the oil tank 1. When the raised operating rod 4 is depressed by foot operation, the hydraulic oil in the pump body 2 is compressed and discharged from the oil supply port 17 into the actuator (not shown) (details of the discharge path are omitted). ). At the same time, the ventilation valve seat 1
No. 4 ventilation hole is closed. Note that the return oil from the actuator is returned into the oil tank 1 by stepping on the open valve pedal 18. Therefore, when the pressure inside the oil tank 1 increases, it will be released through the vent 15. Work is performed by repeating these operations. Although the present invention has been described using a foot-operated hydraulic pump as an example, it is similarly applicable to a manual hydraulic pump.

With the above configuration and operation, the present invention allows the generation of negative pressure in the oil tank, and furthermore, the pressure increase in the oil tank due to the backflow of pressure oil, to be linked to the communication between the atmosphere and the oil tank through operation of the operating stick. In addition, by locking the operating rod to the operating rod stopper after the work is completed, it is possible to easily prevent overflow and dissipation of hydraulic oil when the pump is tipped over during transportation. This is a configuration related to an operating stick and a vent valve of a manual or foot-operated hydraulic pump, which has various characteristics such as:

[Brief explanation of the drawing]

FIG. 1 shows a partially vertical front view of a foot-operated hydraulic pump, which is an example of an embodiment of the present invention, and FIG. 2 shows a schematic plan view thereof. Reference numeral 11 indicates a plunger, and reference numeral 18 indicates an open valve pedal.

Claims (1)

[Scope of utility model registration request] Top projection 1 having a ventilation hole 15 on the top wall of the oil tank
3 is fitted with a vent valve seat 14 made of an elastic body having a through hole communicating with the vent hole 15, and adjusted to a position corresponding to the vent valve seat 14 of the operation rod 4 that swings around the pin 3. A configuration relating to an operating rod and a vent valve of a manual or foot-operated hydraulic pump, characterized in that a vent valve body 13 is provided.