CN104568275B - Device and method for testing friction force of cylinder liner and piston assembly - Google Patents

Abstract

The present invention relates to a testing device and method for the friction force of a cylinder liner and a piston assembly, and belongs to the technical field of friction and wear testing. The power unit of the device is connected to the piston through a piston pin, and the piston is sealed and connected to the cylinder liner through a first gas ring, a second gas ring, and an oil scraper ring installed in a ring groove of the piston. The cylinder liner is sealed and fixed in a cylinder body provided with a heating/cooling cavity, and a baffle is fixed on the cylinder body so that a gap is formed between the baffle and the cylinder body. A friction force sensor is fixed in the gap between the baffle and the cylinder body, and an air supply unit is connected to an air inlet of the piston. The piston has a plurality of air outlets evenly distributed along the circumference of the piston at a position between a ring groove I for installing a first gas ring and a ring groove II for installing a second gas ring. The beneficial effect of the present invention is that the device uses high-pressure gas to simulate the fuel gas pressure, and radially loads multiple piston rings, thereby eliminating the constraint of mechanical radial loading on the circumferential rotation of the piston ring, and is closer to the motion state of the piston ring under the ignition state.

Description

Device and method for testing friction force of cylinder liner and piston assembly

technical field

The invention relates to a device and a method for testing the friction force of a cylinder liner and a piston assembly, belonging to the technical field of friction and wear testing.

Background technique

At present, the research on the friction power consumption of the cylinder liner and piston assembly generally adopts the backward drag method, and this method is tested in the non-ignition state. Due to the lack of radial loading pressure on the piston ring, the measured friction power consumption is different from that under the actual working state. The difference is large. The patent "A Cylinder Liner Piston Ring Parts Friction and Wear Test Equipment" (Patent No.: ZL 200520146126.6) for radial loading of piston rings adopts disc springs to mechanically load piston rings radially, which can simulate the ignition of piston rings. However, the mechanical radial loading method limits the movement of the piston ring in the circumferential direction of the ring groove, which is quite different from the movement mode of the piston ring in the ignition state, and the difference in movement mode directly affects its simulation accuracy At the same time, the mechanical loading method has complex structure, large volume and high inertial force, which is only suitable for studying the friction and wear performance between the cylinder liner and the piston ring, and is not suitable for studying the friction power consumption between the cylinder liner and the piston assembly.

Contents of the invention

In the present invention, the air inlet and the air outlet are arranged on the piston, so that the high-pressure gas enters from the air inlet, exits from the air outlet, and finally acts on the back of the first air ring, the second air ring, and the contact surface of the cylinder liner. , to achieve radial loading on multiple piston rings to simulate the radial pressure on the piston rings in the ignition state; at the same time, only rely on the cylinder liner's own weight to seal the cylinder liner with the cylinder body, so that the cylinder liner is "floating" relative to the cylinder body " state, through the friction sensor fixed in the gap between the baffle plate and the cylinder block, the motor is used to drag the diesel engine backwards to measure the friction force between the cylinder liner and the piston assembly, so as to solve the problem of measuring the friction between the cylinder liner and the piston assembly by the backward dragging method During power consumption, there is a large deviation between the measured value and the actual value due to the lack of radial loading pressure on the piston ring.

The invention provides a test device for the friction force of a cylinder liner and a piston assembly. The device includes a power unit that can provide reciprocating motion, a piston pin, a piston, a first air ring, a second air ring, an oil wiper ring, Cylinder liner, heating/cooling chamber, cylinder body, baffle plate, friction sensor, air supply unit that can provide high-pressure gas, and the power unit that can provide reciprocating motion is connected to the piston through the piston pin, and the piston is installed on the piston The first air ring, the second air ring, and the scraper ring in the ring groove of the cylinder are sealed and connected with the cylinder liner. The cylinder liner is sealed and fixed in the cylinder body with a heating/cooling cavity, and the baffle is fixed on On the cylinder block, a gap is formed between the baffle plate and the cylinder block, and the friction sensor is fixed in the gap between the baffle plate and the cylinder block so that the friction sensor neither contacts the baffle plate nor the cylinder block, The gas supply unit that can provide high-pressure gas is connected to the air inlet hole of the piston, and the piston moves along the piston at the position between the ring groove I where the first gas ring is installed and the ring groove II where the second gas ring is installed. Several air outlet holes are evenly distributed on the circumference.

The power unit that can provide reciprocating motion according to the present invention preferably includes a motor, a shaft coupling, a torque sensor, a flywheel disc, a crankshaft, a bearing, and a connecting rod, and the motor is connected to the crankshaft through a shaft coupling, a torque sensor, and a flywheel disc, The crankshaft is fixed on the cylinder body through a bearing, one end of the connecting rod is connected with the crankshaft, and the other end of the connecting rod is connected with the piston through a piston pin.

The air supply unit that can provide high-pressure gas according to the present invention preferably includes an air compressor, a high-pressure gas cylinder, a pressure relief valve, a high-pressure hose, a high-pressure hard pipe, and a guide rail. , a high-pressure hose and a high-pressure hard pipe are connected to the air intake hole of the piston, and the high-pressure hard pipe is fixed on the baffle through a guide rail.

Another object of the present invention is a method for testing the friction force of a cylinder liner-piston assembly using the above-mentioned device, said method comprising the steps of:

① Turn on the heating/cooling chamber to adjust the inner wall temperature of the cylinder liner;

② Turn on the power unit that can provide reciprocating motion to make the piston reciprocate;

③Open the gas supply unit that can provide high-pressure gas, so that the high-pressure gas enters from the air inlet and exits from the air outlet, and applies radial pressure to the first gas ring and the second gas ring;

④The friction force between the first air ring, the second air ring, the piston and the cylinder liner is transmitted to the friction sensor for measurement through the cylinder liner.

The beneficial effects of the present invention are:

① The device of the present invention uses high-pressure gas to simulate gas pressure, and radially loads multiple piston rings, which eliminates the constraint of mechanical radial loading on the rotation of the piston rings in the circumferential direction, and is closer to the motion state of the piston rings in the ignition state;

②A high-pressure hard tube is used to connect the piston and the high-pressure hose in the present invention, which avoids the influence of the high-frequency oscillating motion of the high-pressure hose during the high-speed reciprocating movement on the test results of the device described in the present invention, and fixes the high-pressure hard tube with guide rails , avoiding the influence of high-pressure hard pipe shaking on the sealing performance of the joint to the greatest extent;

③The friction sensor of the present invention is fixed in the gap between the baffle plate and the cylinder body, so that the friction sensor is neither in contact with the baffle plate nor with the cylinder body, compared with the friction sensor fixed on the moving parts, It not only eliminates the interference of the inertial force of the moving parts on the test results, but also reduces the influence of the fastening pressure between the cylinder liner and the cylinder block on the test results, making the test results more accurate;

④The "floating" liner ensures the seal between the outer wall of the liner and the heating/cooling cavity.

Description of drawings

3 pieces of accompanying drawings of the present invention,

Fig. 1 is the structural representation of cylinder liner and piston assembly friction testing device of the present invention;

Fig. 2 is the structural representation of piston described in the present invention;

Fig. 3 is the sectional view of A-A in Fig. 2;

Among them, 1. Electric motor, 2. Coupling, 3. Torque sensor, 4. Flywheel disc, 5. Crankshaft, 6. Bearing, 7. Connecting rod, 8. Support platform, 9. Piston pin, 10. Piston, 101 , air intake hole, 102, air outlet hole, 11, first air ring, 12, second air ring, 13, oil wiper ring, 14, cylinder liner, 15, heating/cooling chamber, 16, cylinder block, 17 , baffle plate, 18, friction sensor, 19, air compressor, 20, high-pressure cylinder, 21, pressure reducing valve, 22, high-pressure hose, 23, high-pressure hard pipe, 24, guide rail.

detailed description

The following non-limiting examples can enable those skilled in the art to understand the present invention more fully, but do not limit the present invention in any way.

Example 1

A test device for the friction force of a cylinder liner and a piston assembly, the device includes a motor 1, a coupling 2, a torque sensor 3, a flywheel disc 4, a crankshaft 5, a bearing 6, a connecting rod 7, a support platform 8, and a piston pin 9 , piston 10, air intake hole 101, air outlet hole 102, first air ring 11, second air ring 12, scraper ring 13, cylinder liner 14, heating/cooling chamber 15, cylinder block 16, baffle plate 17, Friction sensor 18, air compressor 19, high pressure cylinder 20, pressure reducing valve 21, high pressure hose 22, high pressure hard pipe 23, guide rail 24, described motor 1 and cylinder body 16 are fixed on the support platform 8, described The motor 1 is connected with the crankshaft 5 through the shaft coupling 2, the torque sensor 3, the flywheel disc 4, the crankshaft 5 is fixed on the cylinder block 16 through the bearing 6, one end of the connecting rod 7 is connected with the crankshaft 5, and the connecting rod The other end of 7 is connected to the piston 10 through the piston pin 9, and the piston 10 is sealed with the cylinder liner 14 through the first air ring 11, the second air ring 12, and the oil wiper ring 13 installed in the ring groove of the piston 10. connected, the cylinder liner 14 is sealed and fixed in the cylinder body 16 provided with the heating/cooling chamber 15, the baffle plate 17 is fixed on the cylinder body 16, so that a gap is formed between the baffle plate 17 and the cylinder body 16, and the The friction sensor 18 is fixed in the gap between the baffle 17 and the cylinder 16, so that the friction sensor 18 is neither in contact with the baffle 17 nor with the cylinder 16, and the air compressor 19 passes through the high-pressure cylinder 20 , pressure reducing valve 21, high-pressure hose 22, high-pressure hard pipe 23 are connected with the air inlet 101 of piston 10, and described high-pressure hard pipe 23 is fixed on the baffle plate 17 by guide rail 24, and described piston 10 is installed first Six outlet holes 102 are evenly distributed along the circumference of the piston 10 at the position between the ring groove I of the gas ring 11 and the ring groove II where the second gas ring 12 is installed.

Example 2

A method utilizing the device described in Embodiment 1 to test the frictional force of the cylinder liner and the piston assembly, said method comprising the steps of:

Open the heating/cooling chamber 15, and adjust the temperature of the inner wall of the cylinder liner 14 to 70°C;

② Turn on the motor 1, the motor 1 drives the crankshaft 5 to rotate, and the crankshaft 5 drives the connecting rod 7 to convert the rotational motion into the reciprocating motion of the piston 10;

③ Turn on the air compressor 19, adjust the air pressure to 10MPa, so that the high-pressure gas enters from the air inlet 101 and exits from the air outlet 102, and applies radial pressure to the first air ring 11 and the second air ring 12;

④ The friction force between the first air ring 11, the second air ring 12, the piston 10 and the cylinder liner 14 is transmitted to the friction force sensor 18 through the cylinder liner 14 for measurement.

Claims (4)

1. the test device of a kind of cylinder sleeve and piston component frictional force, it is characterised in that：Described device includes to provide reciprocal The power unit of motion, piston pin (9), piston (10), top compression ring (11), second gas ring (12), oil-scraping ring (13), cylinder Set (14), heating/cooling chamber (15), cylinder body (16), baffle plate (17), friction force sensor (18), gases at high pressure can be provided Air supply unit, described reciprocating power unit be provided to be connected with piston (10) by piston pin (9), the piston (10) by the top compression ring (11) in the annular groove of piston (10), second gas ring (12), oil-scraping ring (13) and cylinder Set (14) is tightly connected, and cylinder sleeve (14) sealing is fixed on and is provided with the cylinder body (16) of heating/cooling chamber (15), the baffle plate (17) it is fixed on cylinder body (16), makes to form gap between baffle plate (17) and cylinder body (16), the friction force sensor (18) is solid Be scheduled in the gap between baffle plate (17) and cylinder body (16), make friction force sensor (18) neither contacted with baffle plate (17) and also with Cylinder body (16) is contacted, and the air supply unit that can provide gases at high pressure is connected with the air admission hole (101) of piston (10), the work Plug (10) is on the position between the annular groove II installed the annular groove I of top compression ring (11) and install second gas ring (12) along work Plug (10) even circumferential is distributed several ventholes (102).

2. device according to claim 1, it is characterised in that：It is described to provide reciprocating power unit including electric Motivation (1), shaft coupling (2), torque sensor (3), Flywheel disc (4), bent axle (5), bearing (6), connecting rod (7), the motor (1) it is connected with bent axle (5) by shaft coupling (2), torque sensor (3), Flywheel disc (4), the bent axle (5) is by bearing (6) It is fixed on cylinder body (16), one end of the connecting rod (7) is connected with bent axle (5), the other end of the connecting rod (7) passes through piston pin (9) it is connected with piston (10).

3. device according to claim 1, it is characterised in that：The air supply unit that gases at high pressure can be provided includes sky Air compressor (19), gas cylinder (20), pressure-reducing valve (21), high-pressure hose (22), high pressure hard tube (23), guide rail (24), it is described Air compressor (19) is by gas cylinder (20), pressure-reducing valve (21), high-pressure hose (22), high pressure hard tube (23) and piston (10) Air admission hole (101) connection, the high pressure hard tube (23) is fixed on baffle plate (17) by guide rail (24).

4. a kind of method that utilization claim 1 described device tests cylinder sleeve and piston component frictional force, it is characterised in that：It is described Method comprises the following steps：

1. heating/cooling chamber (15), the inner wall temperature of regulation cylinder sleeve (14) are opened；

2. opening can provide reciprocating power unit, piston (10) is moved reciprocatingly；

3. opening can provide the air supply unit of gases at high pressure, gases at high pressure is entered from air admission hole (101), by venthole (102) Go out, radial pressure is applied to top compression ring (11) and second gas ring (12)；

4. the frictional force between top compression ring (11), second gas ring (12), piston (10) and cylinder sleeve (14), by cylinder sleeve (14) friction force sensor (18) is passed to measure.