CN1153903C - Fuel oil pump for diesel engine - Google Patents

Abstract

The present invention relates to a fuel oil transfer pump for a diesel engine, which comprises a pump body, a hand pump assembly and a power pump assembly, wherein a hand pump working chamber is communicated with a power pump working chamber; the power pump assembly mainly comprises an oil suction inlet joint, a plunger and a cam transmission mechanism; the oil suction inlet joint presses the plunger by a spring and is connected with a push rod of the cam transmission mechanism, and the plunger is provided with a one-way oil suction valve; a compounding sealing ring is arranged on the push rod. The present invention is characterized in that a one-way valve is arranged on the oil suction inlet joint. The oil transfer pump greatly is characterized in that oil supplying quantity is raised and stabilized, the performance of the oil transfer pump is improved, and the reliability and the practicality of the oil transfer pump are raised.

Description

A kind of fuel oil pump for diesel engine

Technical field

The invention belongs to the diesel engine field, relate to a kind of fuel oil pump of diesel engine oil supply system.

Background technique

The fuel oil pump for diesel engine city when engine operation, utilize camshaft power with the fuel delivery in the fuel tank to the high-pressure service pump filler opening, when motor is not worked, if desired, be exported to pipeline cavity volume between the high-pressure service pump filler opening but hand pump oil is full of it with oil.The diesel engine development trend is the high-power type at present, requires fuel delivery big.There is structural imperfection in existing fuel oil pump, and fuel delivery improves difficulty; The fuel supply flow rate pulsating quantity is big and be difficult to solve fuel oil and bleed and dilute lubricating oil in the cylinder body, causes fastness to pull, and the machine oil anti-channeling leak into outside the pump housing, strengthens deficiencies such as consumption of lubricating oil, befouling environment.Be embodied in: be provided with one-way valve at oil outlet, when the motor pump plunger moves upward, when the motor pump active chamber enters the oil suction operating mode, one-way valve usually occurring opens insufficient, the outer fluid of part inlet port is pushed back the phenomenon of fuel tank, make that the active chamber oil suction is insufficient, cause the pump oil mass to reduce and problem of unstable.This structural imperfection exists, and makes fuel delivery improve difficulty, and the fuel supply flow rate pulsating quantity is big.And the easy hair fastener of fuel feed pump plunger or push rod will cause the flame-out parking of main frame at any time; Fuel oil easily bleeds and dilutes lubricating oil in the cylinder body, causes fastness to pull, and makes the damage at pipe fitting positions such as cylinder body, bent axle.The technical requirements that combined seal ring is installed in the cam drive is very high, radial and axial position degree requirement is arranged all, and promptly the position of seal ring is unique, and assembling difficulty is big, and blocked easily.

Summary of the invention

The present invention is in order to solve raising, stablize fuel delivery and fuel leakage, the problem that the machine oil anti-channeling is leaked, a kind of fuel oil pump for diesel engine is provided, it comprises the pump housing, the hand pump assembly, the motor pump assembly, the hand pump active chamber communicates with the motor pump active chamber, described motor pump assembly mainly comprises the inlet port joint, plunger, cam drive, described inlet port joint is connected with the push rod of described cam drive by the spring compression plunger, described plunger is provided with oil sucting one-way valve, described push rod is provided with combined seal ring, it is characterized in that: described inlet port joint is provided with one-way valve.Owing to set up the inlet port one-way valve, form the motor pump compensated cavity, making it carry out fluid in pressing oily process stores up in advance, when the motor pump active chamber enters the oil suction operating mode, the fluid of compensated cavity is owing to closing of this one-way valve had nowhere to go, can only enter the motor pump active chamber, guarantee the abundant oil suction of motor pump active chamber, thereby guarantee enough, stable pump oil mass.

Description of drawings

Fig. 1, fuel oil pump for diesel engine structural representation of the present invention;

Fig. 2, fuel oil pump for diesel engine structural representation E-E partial enlarged drawing of the present invention;

Fig. 3, fuel oil pump for diesel engine structural representation M-M partial enlarged drawing of the present invention.

Embodiment

As shown in Figure 1, this fuel oil pump for diesel engine comprises the pump housing 1, hand pump assembly 3 and motor pump assembly; The motor pump assembly mainly comprises inlet port joint 6, plunger 8, cam drive 16, inlet port joint 6 compresses plunger 8 by spring 7 and is connected with the push rod 12 of cam drive 16, plunger 8 is provided with oil sucting one-way valve 11, is provided with one-way valve 5 on inlet port joint 6.The cam of cam drive 16 is positioned at oil cylinder 15, and oil cylinder 15 is connected by fastening piece 14 with the pump housing 1, and combined seal ring 19 is installed on the push rod 12.Hand pump active chamber a communicates by passage b with motor pump active chamber d, has constituted motor pump compensated cavity f by the pump housing 1, plunger 8, oil sucting one-way valve 11, inlet port one- way valve 5 and 6 sealings of inlet port joint.Its working principle is as follows: when engine operation, camshaft 16 position as shown begins rotation, drive motor-driven pump work, motor pump work is in two steps: the first step, the oil suction operating mode: cam promotes to move on the push rod 12, push rod 12 promotion motor pump plungers 8 overcome motor pump pump oil spring force and move upward, at this moment, motor pump active chamber d volume enlarges and forms certain degree of vacuum, and fuel-displaced one-way valve 10 is closed, motor pump compensated cavity f volume dwindles, the oil liquid pressure of the pre-storage of compensated cavity f raises, and backs down motor pump oil sucting one-way valve 11, flows to motor pump active chamber d, rise to peak up to push rod 12, active chamber d finishes oil-absorbing process; Second step, press oily operating mode: when camshaft 16 when original position is rotated, cam ejects the position progressively to be reduced, motor pump pump oil spring 7 promotes motor pump plunger 8, push rod 12 moves downward, this moment compensated cavity f volume maximum, form certain degree of vacuum, the outer fluid of the inlet port identical with atmospheric pressure backs down inlet port one-way valve 5 and enters compensated cavity f, and compensated cavity f begins fluid and stores up in advance, and active chamber d volume dwindles simultaneously, fluid forms pressure, motor pump oil sucting one-way valve 11 is closed, and fluid is opened fuel-displaced one-way valve 10 through passage e, from oil outlet to main frame high-pressure service pump inlet port fuel feeding, reduce as far as possible up to push rod 12, finish pre-storage of compensated cavity f fluid and active chamber d and press oily process.This process is a work cycle of motor pump work, and along with the lasting rotation of camshaft, motor pump carries out work cycle again and again, through the outside pump oil of oil outlet.When motor is not worked, when needing hand pump oil, working principle is the same.Owing to set up inlet port one-way valve 5, form motor pump compensated cavity f, making it carry out fluid in pressing oily process stores up in advance, when motor pump active chamber d enters the oil suction operating mode, the fluid of compensated cavity f is owing to closing of inlet port one-way valve 5 had nowhere to go, can only enter motor pump active chamber d, guarantee the abundant oil suction of motor pump active chamber, thereby guarantee enough, stable pump oil mass.Simultaneously, in order to enlarge the Applicable scope of oil transfer pump, between passage b and passage c, set up relief valve 2, when hand pump active chamber a and motor pump active chamber d discharge capacity surplus, pressure rises and backs down relief valve 2, make unnecessary flow get back to compensated cavity f through relief valve 2, the setting of this structure can suitably make the maximum oil absorption demand of discharge capacity greater than high-pressure service pump, thereby under any circumstance guarantees the oil suction demand of high-pressure service pump; Meanwhile, relief valve 2 can limit the maximum pump oil pressure, reduces to leak and avoid overpressure damage seal ring.In order to improve the problem of fuel leakage, the leakage of machine oil anti-channeling, on plunger 8, offer very shallow relief groove 18, as shown in Figure 2; As shown in Figure 1, on push rod 12, also offer very shallow relief groove 13.It is stressed that this relief groove 18,13 has improved the motion of plunger 8 and push rod 12 on the one hand, and " hair fastener and feel nervous " phenomenon of having avoided that existing oil transfer pump usually occurs has played gap sealed effect simultaneously.This clearance seal mechanism is: after leakage loss fluid is through one section narrow slit, sudden enlargement, increase local resistance, thereby reduce leakage loss, former two is that fluid is during through narrow slit therefore, there is " obstruction " phenomenon, along with the increase of time, can on the wall of narrow slit, form " polar molecule layer ", effective gap leakage is reduced, thereby leakage rate is reduced, reach the effect of sealing.As shown in Figure 3, cam drive 16 carries out isolating seal by the combined seal ring on the push rod 12 19 with fuel oil and machine oil, and combined seal ring 19 comprises seal ring 24 and seal ring skeleton 25, offers the groove 20 that goes in ring on seal ring 24, and the bottom is provided with lip limit 23.Being provided with of lip limit 23 solved the engine cylinder-body inner engine oil and taken out of when the to-and-fro motion by push rod, and oil consumption is big, problem of environment pollution caused; And the setting of circular trough makes the fuel leakage oil that may exist 21 enter groove 20 through the hole, then outside draining hole 22 blowdown pumps on the pump housing, stop to leak fuel oil and enter engine cylinder-body, this structure makes the installation of combined seal ring need not be particular about radial direction, only need the control axial position, guarantee that hole 22 and groove 20 get final product at same axial position, greatly reduce assembling difficulty.

Claims (5)

1, a kind of fuel oil pump for diesel engine, it comprises the pump housing, hand pump assembly, motor pump assembly, the hand pump active chamber communicates with the motor pump active chamber, described motor pump assembly mainly comprises inlet port joint, plunger, cam drive, described inlet port joint is connected with the push rod of described cam drive by the spring compression plunger, described plunger is provided with oil sucting one-way valve, and described push rod is provided with combined seal ring, it is characterized in that: described inlet port joint is provided with one-way valve.

2, fuel oil pump for diesel engine as claimed in claim 1 is characterized in that: described oil transfer pump also comprises the relief valve that is arranged between passage (b) and the passage (c).

3, fuel oil pump for diesel engine as claimed in claim 1 is characterized in that: offer relief groove (18) on the described plunger (8).

4, fuel oil pump for diesel engine as claimed in claim 1 is characterized in that: offer relief groove (13) on the described push rod (12).

5, fuel oil pump for diesel engine as claimed in claim 1 is characterized in that: offer circular trough on the seal ring of described combined seal ring, the bottom is provided with the lip limit.

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