JP2002350290A - Rapid compression combustion observation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To always obtain piston speed characteristics of an observation side piston equal to those of an actual engine without depending on only a pressure of compressed fluid. SOLUTION: In this rapid compression combustion observation device, a cylinder 2A, a piston 3A, and a connection rod 4a are arranged on the driving side, while a cylinder, a piston, and a connection rod are arranged on the observation side, and the both connection rods are connected together by means of a crankshaft so that reciprocation of the driving side piston 3A is transmitted to the observation side piston. The driving side cylinder 2A is provided with a capacity variable driving chamber 36 filled with the compressed fluid for pressing down the driving side piston 3A, brake chambers 35a and 35b for braking the driving side piston 3A, a capacity variable exhaust chamber 44 communicated with the braking chamber 35b, and a throttle valve 45 opening/ closing its communication part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a rapid compression combustion observation device as a test device for simulating and observing actual combustion in an engine.

[0002]

2. Description of the Related Art In order to visually observe the combustion occurring in an actual engine, a rapid compression combustion observation apparatus is used as a test apparatus for simulating the same combustion in a pseudo cylinder and observing the same from outside. There is something.

This is configured as shown in FIG. 5
1A is a drive side cylinder device, and 51B is an observation side cylinder device. These drive side cylinder device 51A and observation side cylinder device 51B are cylinders 52A and 52A, respectively.
B, pistons 53A, 53B and connecting rods 54A, 5
4B, and both connecting rods 54A, 54B are connected by a crankshaft 55. Thereby, the drive side piston 5
The reciprocating motion of 3A is transmitted to the observation-side piston 53B, and the observation-side piston 53B also reciprocates once for one reciprocation of the drive-side piston 53A. Drive side cylinder 5
A drive chamber 56 in which compressed air is filled in 2A is provided,
The drive-side piston 53A is pushed down from the top dead center by the compressed air (moves to the right in the drawing). Then, in response to this, the lowering of the observation side piston 53B in the combustion stroke is realized. Observation side cylinder 52B and piston 53B
Is made of glass or the like, and the state of combustion in the combustion chamber 57 can be visually recognized or observed from outside. Therefore, the state of combustion can be analyzed by visually observing this or photographing with a high-speed camera or the like.

In particular, the present device simulates one combustion stroke during actual high-speed operation of the engine. Therefore, the pressure introduced into the drive chamber 56 is high, and the drive-side piston 53A is also rapidly lowered. FIG. 9 shows the piston speed of the observation side piston 53B with respect to the crank angle. In this device, a predetermined angle (60 in this case) from the top dead center (TDC) is shown.
°) (this is called the observation area) to obtain the same piston speed characteristics as the actual engine. Since the combustion stroke need only be reproduced once, it is desirable to decelerate the brake after depressing the driving piston 53A, return to the position near the top dead center by inertia, and stop there. Therefore, the braking chamber 58,
59 are provided. The brake chambers 58 and 59 are like passages that bypass the side surface of the drive-side cylinder 52A, and are provided two at the intermediate portion and the bottom dead center in the stroke region of the drive-side piston 53A.

The driving piston 53A is pushed down by the compressed fluid from the position of the top dead center at the left end shown by the solid line and rapidly descends to the right. With this movement, the air on the rear side (right side) of the drive-side piston 53A is gradually compressed. When the drive-side piston 53A reaches the intermediate position indicated by the dashed line, the high-pressure fluid in the drive chamber 56 bypasses the first brake chamber 58 as shown by the arrow and goes around the back side of the drive-side piston 53A. As a result, the pressure in the driving chamber 56 is reduced, and the first braking of the driving piston 53A is performed. When the drive side piston 53A approaches the vicinity of the bottom dead center indicated by the broken line, the high pressure air on the back side of the drive side piston 53A flows back through the second brake chamber 59 as shown by the arrow. , Wrap around the top surface side of the drive-side piston 53A. As a result, the drive-side piston 53A is not repelled to the top dead center side, but returns to the original position near the top dead center by inertia.

[0006]

By the way, in this device, the characteristic of the piston speed between the driving side piston 53A and the observation side piston 53B is determined only by the pressure of the compressed air introduced into the driving chamber 56. That is, as shown in FIG. 9, it is assumed that the same characteristics as those of the actual machine are obtained when the pressure of the compressed air is medium. This characteristic means that the piston speed of the observation side piston 53B in the observation region is substantially constant as shown in the figure. Then, when the pressure is higher, the piston speed gradually increases in the observation region, and the same characteristics as those of the actual machine cannot be obtained. This means that combustion at high piston speeds cannot be accurately reproduced. Similarly, when the pressure is low, the piston speed gradually decreases in the observation region, and combustion at a low piston speed cannot be accurately reproduced.

Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to always obtain the same piston speed characteristic of the observation side piston as that of an actual engine without depending only on the pressure.

[0008]

The rapid compression combustion observation apparatus according to the present invention includes a driving side cylinder, piston and connecting rod, and an observation side cylinder, piston and connecting rod, and connects both connecting rods with a crankshaft. A driving chamber for transmitting reciprocating motion of the driving piston to the observation piston, and a driving chamber for filling the driving cylinder with a compressed fluid for depressing the driving piston. The capacity is variable.

In this case, it is preferable that the driving side cylinder is provided with an adjusting piston capable of adjusting a position for partitioning the driving chamber between the driving side piston and the driving side piston.

[0010] Preferably, the adjusting piston is manually adjustable in position by means of a feed screw and a handle.

[0011] A brake chamber for braking the drive-side piston depressed by the compressed fluid to the drive-side cylinder, an exhaust chamber communicated with the brake chamber, and a throttle valve for opening and closing the communication portion. Is preferably provided.

Further, the rapid compression combustion observation device according to the present invention includes a driving side cylinder, piston and connecting rod, and an observation side cylinder, piston and connecting rod, and connects both connecting rods with a crankshaft. A drive chamber for transmitting the reciprocating motion of the piston to the observation side piston, and filling the drive side cylinder with a compressed fluid for pushing down the drive side piston, and a drive side pushed down by the compressed fluid. A brake chamber for braking the piston, an exhaust chamber communicated with the brake chamber, and a throttle valve for opening and closing the communicating portion are provided.

Here, the capacity of the exhaust chamber is preferably variable.

Preferably, a part of the exhaust chamber is defined by an exhaust chamber adjusting piston whose position can be adjusted.

Preferably, the position of the exhaust chamber adjusting piston can be manually adjusted by a feed screw and a handle.

It is preferable that the brake chamber is provided at an intermediate portion and a bottom dead center portion in a stroke region of the drive side piston, respectively, and the exhaust chamber communicates with the brake chamber at the bottom dead center portion.

[0017]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIGS. 3 and 4 show the entirety of the rapid compression combustion observation apparatus according to this embodiment. This apparatus includes a driving cylinder device 1A and an observation cylinder device 1B arranged in parallel with each other. The driving cylinder device 1A and the observation cylinder device 1B are respectively composed of cylinders 2A and 2B and a piston 3B.
A, 3B and connecting rods 4A, 4B. The two connecting rods 4A and 4B are connected by a crankshaft 5 to transmit the reciprocating motion of the driving piston 3A to the observing piston 3B, and the observing piston 53B also reciprocates once for each reciprocating motion of the driving piston 3A. It is made to let.
These drive side cylinder device 1A and observation side cylinder device 1
B and the crankshaft 5 are supported on a base 10. A brake 11 for stopping and holding the brake is provided on the crankshaft 5. The brake 11 is mounted on the base 10 via the boss 12 on the crankshaft 5 and the brake disk 13 is selected. And a caliper 14 that is to be gripped.

The observation side cylinder device 1B is configured as shown in FIG. That is, the observation side cylinder 2B is horizontally supported by the pair of legs 15 (see FIG. 4), and the observation side piston 3B is slidably inserted into the observation side cylinder 2B. The observation side piston 3B is formed in a relatively long cylindrical shape, and one end of the connecting rod 4B is rotatably connected to a lower end located on the right side in the drawing via a pin 16. The other end of the connecting rod 4B is rotatably connected to the crankshaft 5 shown in FIG. A window 16 made of a heat-resistant and transparent material such as glass is formed at the upper end located on the left side of the observation side piston 3B in the drawing so that the state of combustion in the combustion chamber 17 can be observed from the back side of the piston 3B. Has become.
The observation side cylinder device 1B simulates a direct injection diesel engine. A combustion chamber 17 is recessed from the top surface of a piston 3B, and an injection port of a fuel injection nozzle 18 protrudes into the combustion chamber 17. Thus, fuel injection is performed directly into the combustion chamber 17.

Observation side cylinder 2B and observation side piston 3B
The bracket 20 fixed to the outer peripheral portion of the observation side cylinder 2B is extended into the piston 3B through the notch 19, and the reflecting mirror 21 is obliquely attached to the extended end. . Therefore, the state of combustion seen from the back side of the piston 3B through the window 16 can be visually recognized from directly above via the reflecting mirror 21.

The cylinder head 22B is provided with the aforementioned fuel injection nozzle 18 and a window 23 for viewing the inside of the combustion chamber 17 from the top surface of the head. The window 23 is also made of a heat-resistant and transparent material such as glass. A peephole 24 is provided in front of the window 23, and the inside of the combustion chamber 17 can be visually recognized from the head side through the peephole 24 and the window 23.

The drive side cylinder device 1A is configured as shown in FIG. That is, the driving cylinder 2A is horizontally supported by the pair of brackets 25 (see FIG. 4), and the driving piston 3A is slidably inserted into the driving cylinder 2A. The drive-side piston 3A is formed in a thin disk shape, and the top surface 26 is slightly rounded. The connecting rod 4A has a divided structure, and includes a fixed connecting rod 28 fixed to the back surface 27 of the piston 3A, and a movable connecting rod 3 rotatably connected to the fixed connecting rod 28 via a pin 29.
It consists of 0. The end of the movable connecting rod 30 is rotatably connected to the crankshaft 5 shown in FIG. The connecting portion between the fixed connecting rod 28 and the movable connecting rod 30 is inserted into the cylindrical guide member 31 to guide the reciprocating movement thereof.

The driving side cylinder 2A is connected to the observation side cylinder 2B.
Larger diameter. The inner wall of the driving cylinder 2A is formed of a thin cylindrical cylinder liner 32. A first gap 33a and a second gap 33b are provided between the drive side cylinder 2A and the cylinder liner 32 at an intermediate portion and a bottom dead center portion of the stroke region of the drive side piston 3A. A pair of first braking holes 34a and second braking holes 34b communicating with the one gap 33a and the second gap 33b are provided. These first gaps 33a
The first braking chamber 35a and the second braking chamber 35b are defined by the pair of the first braking chamber 34a and the second braking hole 34b. The first braking hole 34a,
It is necessary to set the separation distance between the protrusions 34a to be equal to or greater than the thickness of the sliding surface of the piston 3A, and is substantially equal to the thickness here. This is the same for the separation distance between the second braking holes 34b.

On the top surface 26 side of the driving piston 3A, a driving chamber 36 for filling a compressed fluid for pushing down the driving piston 3A rightward in the drawing is formed. Here, the compressed fluid is compressed air. A drive chamber 36 is provided with an inlet 37 for compressed air, and as shown in FIG.
Compressed air is supplied from a compressor 60 installed outside. The supply of the compressed air is selectively performed by opening and closing the valve 61.

In particular, in this embodiment, the capacity of the drive chamber 36 is variable. That is, the adjustment piston 38 is slidably disposed in the drive side cylinder 2A, and
Is partly divided. The adjustment piston 38 is arranged to face the top surface 26 of the drive-side piston 3A, and defines a drive chamber 36 with the drive-side piston 3A. A feed screw 39 is fixedly mounted at the center of the adjusting piston 38.
Extends to the opposite side of the connecting rod 4A to
After being screwed into the A female screw 40, it protrudes from the drive side cylinder 2A. The feed screw 39 is externally provided with a lock nut 41.
Can be fixed selectively. A handle 42 for rotating the feed screw 39 is detachably attached to the tip of the feed screw 39. According to this, the handle 42
Is turned by hand to rotate the feed screw 39,
The position of the adjustment piston 38 in the cylinder axis direction can be manually changed, and the capacity of the drive chamber 36 can be changed.

In the present embodiment, the second brake chamber 35
An exhaust chamber 44 communicated with b through the communication passage 43 and a throttle valve 45 for opening and closing the communication passage 43 are provided. That is, the exhaust cylinder 46 is attached to the upper surface of the drive side cylinder 2A (omitted in FIG. 3), and the exhaust chamber adjusting piston 47 is slidably provided in the exhaust cylinder 46, and is partially partitioned by this. An exhaust chamber 44 is defined. The communication passage 43 is formed in a right angle by drilling holes in the drive side cylinder 2A and the exhaust cylinder 46, respectively. The throttle valve 45 includes a bolt 47 and a lock nut 48. When the bolt 47 is tightened as far as it will go, the communication passage 43 is closed, and when the bolt 47 is loosened, the communication passage 4 is adjusted according to the amount of loosening.
3 is released. The exhaust chamber adjusting piston 47 can be manually adjusted by a feed screw 49 and a handle 50 similarly to the adjusting piston 38. Therefore, the capacity of the exhaust chamber 44 is also variable. The feed screw 49 can be selectively fixed by a lock nut 49a.

Next, a method of using the present apparatus will be described. FIG.
First, the crankshaft 5 is completely braked by the brake 11 with the drive-side piston 3A positioned at the top dead center (the position indicated by the solid line in FIG. 1). As a result, the driving piston 3A does not move. The driving piston 3
The phase of A and the observation-side piston 3B are slightly shifted, and at this time, the observation-side piston 3B is positioned before the top dead center (see FIG. 9). Next, the valve 61 is opened to fill the drive chamber 36 with the compressed air of the compressor 60, and the pressure in the drive chamber 36 is sufficiently increased. Then, the valve 61 is closed to seal the drive chamber 36. Thereafter, the brake 11 is instantaneously released, and the driving-side piston 3A is rapidly lowered at a high pressure. Then, the observation side piston 3B once goes to the top dead center and further descends from the top dead center. If the fuel is injected from the fuel injection nozzle 18 near the top dead center to perform combustion, the actual engine combustion stroke is reduced. Can be simulated. The state of this combustion is window 1
It can be visually observed from outside or photographed by a high-speed camera through 6, 23.

The method of braking the drive side piston 3A is basically the same as the conventional method. That is, the driving side piston 3A is 3A '.
As shown by the dashed line (FIG. 5), the first braking holes 34a,
As shown in FIG. 5, a part of the compressed air in the driving chamber 36 is moved to the intermediate position between the first braking chamber 35a and the first braking chamber 35a.
And bypasses to the back side of the drive side piston 3A. As a result, the pressure in the driving chamber 36 is reduced, and the first braking of the driving piston 3A is performed. Drive piston 3
When A reaches the bottom dead center between the second braking holes 34b, 34b as indicated by 3A ″ (broken line in FIG. 5), the high-pressure air on the back side of the driving-side piston 3A A part flows backward by bypassing the second brake chamber 35b as shown by an arrow in FIG. 5, and wraps around the top surface side of the drive-side piston 3A.
As a result, the drive side piston 3A is not repelled to the top dead center side, and returns to the original position near the top dead center by inertia.

FIGS. 6 and 7 show the piston speed of the observation side piston 3B with respect to the crank angle as in FIG. This device also obtains the same piston speed characteristics as an actual engine in an observation region from a top dead center (TDC) to a predetermined angle = 60 °. Here, the characteristic means that the piston speed is substantially constant in the observation region.

If the same piston speed characteristic as that of an actual engine cannot be obtained, the piston speed is controlled as follows.

First, a method of changing the capacity of the driving chamber 36 is described. That is, as shown by a0 in FIG. 6, the pressure is increased to reproduce the combustion at a high piston speed,
As a result, if the same characteristic that the piston speed increases cannot be obtained, the capacity of the drive chamber 36 is reduced before driving the drive-side piston 3A.
Then, since the pressure drop with respect to the lowering of the piston becomes remarkable, the piston speed is further reduced in the later stage of the movement as shown by a1, and the same characteristics can be obtained. On the other hand, as shown by b0, if the same characteristic that the piston speed is reduced by trying to reproduce combustion at a low piston speed and the piston speed is reduced cannot be obtained, the driving side piston 3A is driven in advance. Before the driving, the capacity of the driving chamber 36 is increased. Then, since the pressure drop with respect to the downward movement of the piston becomes slower, the piston speed is further increased in the later stage of the movement as shown by b1, and the same characteristics can be obtained.

Next, a method of changing the opening of the throttle valve 45 will be described. As shown by c0 in FIG. 7, when the pressure is increased in order to reproduce combustion at a high piston speed, and as a result, the same characteristic that the piston speed is increased cannot be obtained, the drive side piston 3A is set in advance. Before driving, the opening degree of the throttle valve 45 is made smaller. During the lowering of the drive-side piston 3A, the pressure on the rear side gradually increases. When the throttle valve 45 is open, a part of the air on the rear side is exhausted to the exhaust chamber 44 through the communication passage 43. However, when the opening degree of the throttle valve 45 is reduced, the amount of exhaust to the exhaust chamber 44 decreases while the drive-side piston 3A is descending, and the pressure on the rear side becomes difficult to decrease, so that the braking becomes stronger, as shown by c1. The same characteristics can be obtained by lowering the piston speed in the later stage of the movement. On the other hand, d
As shown by 0, when the pressure is reduced in order to reproduce the combustion at a low piston speed, and the same characteristic that the piston speed is reduced cannot be obtained, if the driving side piston 3A is previously driven, The degree of opening of the throttle valve 45 is increased in advance. Then, the amount of exhaust to the exhaust chamber 44 increases while the drive-side piston 3A descends, and the pressure on the back side of the exhaust becomes difficult to increase.
As shown by d1, the same characteristic can be obtained by further increasing the piston speed in the latter half of the movement.

On the other hand, there is a method of changing the degree of braking by changing the capacity of the exhaust chamber 44. That is, the throttle valve 45 is fixed at a fixed opening other than zero, for example, fully open. If the capacity of the exhaust chamber 44 is reduced, the exhaust to the exhaust chamber 44 becomes difficult during the lowering of the drive-side piston 3A (because the pressure in the exhaust chamber 44 tends to increase), so that the pressure on the back side is reduced. It becomes difficult to fall and braking is strengthened. Conversely, if the capacity of the exhaust chamber 44 is increased, the exhaust to the exhaust chamber 44 becomes easier during the descent of the drive-side piston 3A (because the pressure in the exhaust chamber 44 is unlikely to increase), so that the pressure on the rear side is increased. And the braking is weakened.

As described above, according to the present apparatus, the driving chamber 36
The piston speed of the drive-side piston 3A can be controlled by changing the capacity of the piston 3A, by changing the opening of the throttle valve 45, or by changing the capacity of the exhaust chamber 44. The piston speed of the side piston 3B can be controlled.
As a result, without depending only on the pressure of the drive chamber 36,
The piston speed characteristic of the observation side piston 3B can always be the same as that of the actual engine.

In the above-described embodiment, the piston speed is constant up to 60 ° from the top dead center. However, any piston speed characteristic may be used.
Regardless of the actual piston speed characteristic, the same method can easily reproduce the same characteristic.

Various other embodiments of the present invention are conceivable. For example, the throttle valve may be a butterfly valve as shown in FIG. The communication passage 43 may be omitted, and the brake chamber and the exhaust chamber may be directly communicated with each other, and the communication portion may be opened and closed by a throttle valve. Conversely, a part of the drive chamber may be used as a sub chamber, and the capacity of the sub chamber may be changed. The compressed fluid may be other than compressed air.

[0037]

In summary, according to the present invention, an excellent effect of always obtaining the same piston speed characteristic of the observation side piston as that of the actual engine without depending only on the pressure of the compressed fluid is exhibited. .

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view showing a drive side cylinder device according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional side view showing an observation side cylinder device according to an embodiment of the present invention.

FIG. 3 is a plan view showing the entire rapid compression combustion observation device according to the embodiment of the present invention.

FIG. 4 is a left side view of the same.

FIG. 5 is a schematic configuration diagram of the same.

FIG. 6 is a piston speed characteristic diagram for explaining the effect of the present embodiment.

FIG. 7 is a piston speed characteristic diagram for explaining the effect of the present embodiment.

FIG. 8 is a schematic configuration diagram showing a conventional rapid compression combustion observation device.

FIG. 9 is a piston speed characteristic diagram in a conventional device.

[Explanation of symbols]

 2A Drive-side cylinder 2B Observation-side cylinder 3A Drive-side piston 3B Observation-side piston 4A Drive-side connecting rod 4B Observation-side connecting rod 5 Crankshaft 35a First brake chamber 35b Second brake chamber 36 Drive chamber 38 Adjusting piston 39 Feed screw 42 Handle 43 continuous Passageway 44 Exhaust chamber 45 Throttle valve 47 Exhaust chamber adjusting piston 49 Feed screw 50 Handle

Claims (9)

[Claims] 1. A driving side cylinder, piston and connecting rod, and an observation side cylinder, piston and connecting rod are connected to each other by a crankshaft, and reciprocating motion of the driving side piston is transmitted to the observation side piston. A driving chamber for filling the driving-side cylinder with a compressed fluid for depressing the driving-side piston, wherein the capacity of the driving chamber is variable. . 2. The rapid compression combustion observation device according to claim 1, wherein the drive-side cylinder is provided with a position-adjustable adjusting piston that partitions the drive chamber between the drive-side cylinder and the drive-side piston. 3. The rapid compression combustion observation device according to claim 2, wherein the position of the adjustment piston can be manually adjusted by a feed screw and a handle. 4. A brake chamber for braking the drive-side piston depressed by the compressed fluid to the drive-side cylinder, an exhaust chamber communicated with the brake chamber, and a throttle for opening and closing the communication portion. The rapid compression combustion observation device according to any one of claims 1 to 3, further comprising a valve. 5. A driving-side cylinder, piston and connecting rod, and an observation-side cylinder, piston and connecting rod, wherein both connecting rods are connected by a crankshaft, and reciprocating motion of the driving-side piston is transmitted to the observation-side piston. A driving chamber for filling the driving-side cylinder with a compressed fluid for depressing the driving-side piston, a braking chamber for braking the driving-side piston depressed by the compressed fluid, An apparatus for observing rapid compression combustion, comprising: an exhaust chamber connected to a brake chamber; and a throttle valve for opening and closing the communication section. 6. The exhaust chamber has a variable capacity.
The rapid compression combustion observation device described in the above. 7. The rapid compression combustion observation device according to claim 6, wherein a part of the exhaust chamber is defined by an exhaust chamber adjusting piston whose position can be adjusted. 8. The rapid compression combustion observation device according to claim 7, wherein the position of the exhaust chamber adjustment piston can be manually adjusted by a feed screw and a handle. 9. The brake chamber is provided at an intermediate portion and a bottom dead center portion in a stroke region of the drive-side piston, and the exhaust chamber communicates with the brake chamber at the bottom dead center portion. 9. The rapid compression combustion observation device according to any one of claims 8 to 8.