JPH068876U - Unloader - Google Patents

Abstract

(57) [Summary] [Object] To provide an unloader 86 having a simple structure and a small size. [Structure] A piston 62 is movable in the upward protrusion 50 of the discharge side casing 18 in the flow direction of the cleaning liquid, and receives hydraulic pressure from the uniflow type piston pump 10 side and the gun nozzle 60 side. The check valve 70 is incorporated in the inner hole of the downstream end of the piston 62, and prevents the backflow of the cleaning liquid from the gun nozzle 60 side to the uniflow type piston pump 10 side. Through hole 52
Is connected to the suction side casing 14 via the return pipe 56 and communicates with the center hole 68 via the annular groove 82 and the inclined passage 84 when the piston 62 is in a position in contact with the step portion 64. As shown in FIG.
Formed to 50.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an unloader mounted on a washing machine or the like, and more particularly to an unloader having a simplified structure.

[0002]

[Prior art]

 In the cleaning machine, the gun nozzle is connected to the discharge side of the pump, and the operator can open and close the gun nozzle to control the injection and suspension of the cleaning liquid from the gun nozzle. Also, since the rotational power of the pump is useless when the operator closes the gun nozzle, an unloader is installed on the discharge side of the pump so that the pump has almost no load.

A conventional unloader (eg, Japanese Utility Model Laid-Open No. Sho 63-3575) is provided with a check valve for preventing backflow from the gun nozzle to the pump and an opening valve element for opening the discharge side of the pump. At the same time, the pressure on the gun nozzle side is guided from the check valve to the operating member such as the piston, and when the gun nozzle is closed and the pressure on the gun nozzle side increases, the operating member is displaced and the opening valve body is closed to open. It is supposed to switch.

[0004]

[Problems to be solved by the device]

 In the conventional unloader, the opening valve element is required separately from the operating member, and the member for transmitting the displacement of the operating member to the opening valve element is also required, which makes the structure complicated and large-sized.

An object of the present invention is to provide an unloader having a simplified structure and a small size.

[0006]

[Means for Solving the Problems]

 The invention will be described using the reference numerals of the drawings corresponding to the embodiments. The unloader (86) of this invention has the following components (a) to (f). (A) The piston (62) is arranged so as to be movable in the flow direction of the fluid in the discharge conduit (50) connected to the discharge side of the pump (10). (B) The movement range of the piston (62) Stopper (64, 66) for limiting (c) Energizing means (78) for urging the piston (62) to the upstream side (d) Formed in the piston (62) to discharge the fluid discharged from the pump (10) to the piston ( Fluid passage (68) to be passed through in (62) (e) Check valve (70) (f) Piston (62) that is installed in the piston (62) and prevents fluid from flowing backward through the fluid passage (68) ) Is located in the upstream position, the fluid is formed in the discharge pipe line (50) so as to communicate with the portion of the fluid passageway (68) upstream of the fluid passageway (68) and discharges the fluid in the fluid passageway (68). Outlet (54)

[0007]

[Action]

 When elements downstream of the piston (62), such as the gun nozzle (60), are open, the pressure downstream of the piston (62) is low. As a result, the piston (62) receives the fluid discharged from the pump (10) and moves downstream against the urging force of the urging means (78) until it is limited by the stopper (66). It slides in the discharge conduit (50) and is held at the downstream position. Therefore, the discharge port (54) of the discharge pipe line (50) is disconnected from the fluid passageway (68) of the piston (62), and the discharge side of the pump (10) maintains high pressure. On the other hand, the check valve (70) is also opened because the amount of fluid on the downstream side is small, so that the fluid discharged from the pump (10) is released from the fluid passageway (68) of the piston (62) and the check valve. It is led to the gun nozzle (60) etc. via (70) and consumed.

When a downstream element of the piston (62) such as the gun nozzle (60) is closed, the downstream side of the piston (62) is closed and the pressure increases. As a result, the check valve (70) is closed, and the piston (62) is pushed upstream by the urging force of the urging means (78) until it is restricted by the stopper (64). It slides inside and is held at the upstream position. Therefore, the discharge port (54) of the discharge conduit (50) is in communication with the fluid passageway (68) of the piston (62), and the fluid discharged from the pump (10) is discharged from the discharge port (54). , The discharge pressure of the pump (10) drops to almost zero, and the pump (10) operates almost without load.

[0009]

【Example】

 The present invention will be described below with reference to the embodiments shown in the drawings. 1 and 2 are structural views of the uniflow type piston pump 10 and the unloader 86 shown in a state where the unloader 86 holds and releases the load of the uniflow type piston pump 10. The uniflow type piston pump 10 of the embodiment is installed in a washing machine. The crankcase 12 is fixed to the base at the bottom, and the suction side casing 14, the cylinder pipe 16 and the discharge side casing 18 are arranged in order from the crankcase 12 side, and the crankcase 12 is tightened with a tightening bolt (not shown). The case 12 is tightened and is in a joined state. The suction pipe 20 is connected to the lower portion of the suction side casing 14, is bent at a substantially right angle, and has a suction port 22 oriented in the horizontal direction at the lower portion.

The piston rod 24 is coupled to a cross head 26, which is guided in an axial direction in a guide portion of the crankcase 12, at a base end side, and reciprocates as a crankshaft (not shown) in the crankcase 12 rotates. Move. The oil seal 28 and the low-pressure seal 30 are provided at the end of the guide portion of the crosshead 26 in the crankcase 12 and at the joint between the crankcase 12 and the suction-side casing 14, respectively, and on the inner circumference side, the piston rod 28 and the low-pressure seal 30 are provided. The sliding contact of 24 seals against the lubricating oil in the crankcase 12 and the cleaning liquid in the suction side casing 14. The valve body 32 and the stopper 34 with the through hole are mounted on the tip end portion of the piston rod 24 with a predetermined distance in the axial direction of the piston rod 24 so that the stopper 34 with the through hole is on the tip side of the valve body 32. The nut 36 is fixed to the piston rod 24 by screwing the nut 36 from the tip side of the piston rod 24. The valve seat 38 is loosely fitted to the piston rod 24 between the valve body 32 and the stopper 34 with a through hole, and the piston packing 40 is fitted to the outer peripheral side of the valve seat 38 and slidably contacts the cylinder pipe 16. The pump chamber 42 is formed in the cylinder pipe 16 ahead of the piston rod 24, and the suction valve 44 is constituted by the valve body 32 and the valve seat 38, and guides the cleaning liquid from the suction side casing 14 to the pump chamber 42 in one direction. The discharge valve 46 is arranged at the boundary between the cylinder pipe 16 and the discharge side casing 18, and guides the cleaning liquid from the pump chamber 42 to the discharge side casing 18 in one direction.

The suction-side casing 14 and the discharge-side casing 18 are respectively provided with upper projecting portions 48 and 50 which face each other in the horizontal direction, and the through holes 52 and 54 are located on the opposite side of the upper projecting portions 48 and 50. They are formed on the surface and communicate with each other by a return pipe 56. The connection fitting 58 is screwed onto the upper end of the upper protruding portion 50, and the upper end is connected to the gun nozzle 60 via a hose (not shown).

The piston 62 is fitted into the upper protrusion 50 so as to be movable in the upper protrusion 50 in the direction of the center line of the upper protrusion 50. Limited by the lower end 66 of section 64 and fitting 58. The center hole 68 extends along the center line of the piston 62 from the upstream end surface of the center hole 68 to the check valve 70. The check valve 70 is incorporated in the inner hole at the downstream end of the piston 62, and blocks the backflow of the cleaning liquid from the gun nozzle 60 side to the central hole 68 side. The check valve 70 is mounted on the peripheral wall of the inner hole at the downstream end of the piston 62, and is seated upstream of the snap ring 72 and at the opening edge of the downstream end of the center hole 68. It has a free valve body 74 and a compression coil spring 76 that is compressed between the snap ring 72 and the valve body 74 and biases the valve body 74 toward the central hole 68. One end of the compression coil spring 78 is fitted to the reduced diameter portion of the connecting fitting 58 on the upstream side, and is compressed between the step portion on the outer peripheral side of the connecting fitting 58 and the downstream end surface of the piston 62. , The piston 62 is urged to the upstream side. The three piston rings 80 are fitted on the outer peripheral side of the piston 62 and slidably contact the inner periphery of the upper protruding portion 50 to seal the annular groove 82 and the through hole 54 on the outer peripheral side of the piston 62. The annular groove 82 is formed on the outer peripheral portion of the piston 62 so as to coincide with the through hole 54 when the piston 62 is at the upstream position (FIG. 2), that is, when the piston 62 is in contact with the step portion 64. It is formed. The plurality of inclined passages 84 communicate with the central hole 68 and the annular groove 82, and extend obliquely along the flow of the cleaning liquid from the central hole 68 to the annular groove 82. The piston 62, the check valve 70, the through hole 54, and the like constitute an unloader 86 that suppresses the power loss of the uniflow type piston pump 10 by placing the uniflow type piston pump 10 in a substantially unloaded state when the gun nozzle 60 is closed.

The operation of the embodiment will be described. During the suction stroke in which the piston rod 24 moves toward the crankcase 12, the volume of the pump chamber 42 increases, the valve seat 38 comes into contact with the stopper 34 with a through hole, and the suction valve 44 opens. The discharge valve 46 is closed. As a result, the cleaning liquid is sucked into the pump chamber 42 from the suction side casing 14 through the suction valve 44.

During the discharge stroke in which the piston rod 24 moves toward the pump chamber 42, the volume of the pump chamber 42 decreases, the valve seat 38 comes into contact with the valve body 32, and the intake valve 44 closes. Then, the discharge valve 46 is opened. As a result, the cleaning liquid is discharged from the pump chamber 42 to the discharge-side casing 18.

When an operator opens the gun nozzle 60, the hydraulic pressure in the connecting fitting 58 decreases. As a result, the piston 62 receives the cleaning liquid discharged from the discharge valve 46, and resists the urging force of the compression coil spring 78 until it abuts the lower end 66 of the connecting fitting 58. It slides inside and is held at the downstream position (Fig. 1). Therefore, the communication hole 54 is disconnected from the annular groove 82, the cleaning liquid in the central hole 68 is not discharged through the through hole 54, and the liquid pressure in the central hole 68 is large. On the other hand, in the check valve 70, since the liquid pressure on the gun nozzle 60 side is small, the valve body 74 is separated from the downstream end of the central hole 68 against the compression coil spring 76, and the central hole 68 is opened. The cleaning liquid discharged from the uniflow type piston pump 10 is pressure-fed (arrow A in FIG. 1) to the gun nozzle 60 via the central hole 68 of the piston 62 and the check valve 70, and is ejected from the gun nozzle 60.

When the operator closes the gun nozzle 60, the hydraulic pressure on the gun nozzle 60 side from the connection fitting 58 rises. As a result, the valve element 74 is displaced according to the biasing force of the compression coil spring 76 and is seated at the opening edge portion of the downstream end of the central hole 68, and the check valve 70 closes the central hole 68. The piston 62 slides in the upward projecting portion 50 toward the upstream side by the biasing force of the compression coil spring 78, and is held at the position in contact with the step portion 64 (FIG. 2). As a result, the annular groove 82 of the piston 62 coincides with the through hole 54, and the cleaning liquid in the central hole 68 is sent to the through hole 54 via the inclined passage 84 and the annular groove 82. As a result, the cleaning liquid circulates through the pump chamber 42, the discharge valve 46, the central hole 68, the inclined passage 84, the annular groove 82, the through hole 54, the return pipe 56, the through hole 52, the suction side casing 14, and the suction valve 44. (Fig. 2 arrow B), the hydraulic pressure in the central hole 68 as the hydraulic pressure on the discharge side of the uniflow type piston pump 10 becomes almost zero, and the uniflow type piston pump 10 becomes almost unloaded, resulting in power loss. Is suppressed.

In the illustrated embodiment, the through hole 54 is connected to the suction side casing 14 via the return pipe 56, but the through hole 54 is connected to the cleaning liquid tank via a hose, and the through hole 54 It is also possible to bring the uniflow type piston pump 10 into an almost no-load operation state by returning the washing solution from the above to the washing solution tank. In the illustrated embodiment, the uniflow type piston pump 10 is used, but the present invention can be applied to other pumps other than the uniflow type piston pump 10.

[0018]

[Effect of device]

 According to this invention, the piston that detects and changes the pressure change due to switching between use and non-use of the fluid directly opens and closes the discharge port for making the pump discharge pressure almost zero. Since it is not necessary to prepare a valve body or the like for opening and closing separately from the piston, the unloader has a simple structure and is small in size.

[Brief description of drawings]

FIG. 1 is a structural diagram of a uniflow type piston pump and an unloader shown in a state where an unloader holds a load of a uniflow type piston pump.

FIG. 2 is a structural diagram of the uniflow type piston pump and the unloader shown in a state where the unloader releases the load of the uniflow type piston pump.

[Explanation of symbols]

 10 Uniflow Type Piston Pump (Pump) 50 Upper Projection (Discharge Pipeline) 54 Through Hole (Discharge Port) 62 Piston 64 Step (Stopper) 66 Lower End (Stopper) 68 Center Hole (Fluid Passage) 70 Check Valve 78 Compression Coil spring (biasing means) 86 Unloader

Claims (1)

[Scope of utility model registration request] 1. A piston (62) disposed so as to be movable in a fluid flow direction in a discharge pipe line (50) connected to a discharge side of a pump (10), and movement of the piston (62). Stopper (64, 66) for limiting the range, biasing means (78) for biasing the piston (62) to the upstream side, and fluid discharged from the pump (10) formed in the piston (62) A fluid passageway (68) through which the piston (62) passes, a check valve (70) assembled to the piston (62) to prevent the fluid from flowing backward through the fluid passageway (68), and the piston The fluid passageway (68) is formed in the discharge conduit (50) so as to communicate with the portion of the fluid passageway (68) upstream of the fluid passageway (68) when the (62) is at the upstream side position. ) And a discharge port (54) for discharging the fluid.