JPS59110820A - Compression relief engine retarder for outer cylinder internal combustion engine - Google Patents

Abstract

A compression release engine retarder for a multi-cylinder four-stroke cycle engine is disclosed. The retarder incorporates an hydraulic pulse generator (85) which in one embodiment comprises a multi-chamber positive displacement pump of the piston (146) and cylinder (144) type which is positively driven at engine speed or at half engine speed in synchronism with the engine crankshaft (86). Means (84,96,97) are provided to adjust the timing of the hydraulic pulses so as to control precisely the opening of the engine exhaust valves and to maximize the compression release retarding power developed by the engine. Additional means (182,184,186,188,190,192,194) are provided to control the timing of the hydraulic pulses in response to the boost pressure in the engine inlet manifold produced by the engine turbocharger.

Description

DETAILED DESCRIPTION OF THE INVENTION A decompression engine retarder for a multi-cylinder four-stroke engine is disclosed. The retarder incorporates a hydraulic pulse generator (185), which in one embodiment includes a piston (146) and a cylinder (185).
144), which is actively driven at engine speed or half engine speed in synchronization with engine crank 1141I (86).

Means for adjusting timing f:m of hydraulic pressure pulse (84, 96
, 97) to accurately control the opening of the engine exhaust valve and to maximize the decompression deceleration forces produced by the engine. Further, means (182, 184) for controlling the timing of the hydraulic pressure pulses in response to the increased pressure in the engine inlet manifold produced by the engine turbocharger.
, 186, 188, 190° 192, 194) (FIG. 4A) 6 This invention relates generally to engine retarders for use in multi-cylinder four-stroke internal combustion engines. More particularly, the present invention relates to a hydraulic pulse generator for sequentially opening exhaust valves of an internal combustion engine to provide a decompression engine deceleration function during braking operations.

It is known that drum or disc type wheel brakes can absorb large amounts of energy in a short period of time.

The absorbed energy is converted to heat, causing the temperature of the braking mechanism to rapidly rise to a level that renders the friction surfaces and other parts of the mechanism ineffective. Because repeated use of wheel brakes under such conditions is impractical.

It relies on an auxiliary reduction gear.

This type of auxiliary equipment is equipped with a hydraulic straddle-power reduction gear and is capable of converting the kinetic energy of the vehicle into heat by means of fluid friction or magnetic vortices, which can be dissipated via a suitable heat exchanger. .

Other auxiliary reduction devices include an exhaust brake to prevent the flow of exhaust gases or air through the exhaust system and a decompression retarder mechanism to compress the intake air during the compression stroke of a four-stroke engine. The required energy is dissipated by exhausting compressed air through the exhaust system during the engine's expansion stroke.In the case of engine decompression retarders, a portion of the vehicle's dynamic energy is dissipated through the engine cooling system. Another part of the dynamic energy is dissipated through the engine exhaust system.In the case of exhaust braking, the dynamic energy of the vehicle is dissipated only as heat through the engine cooling system.

One major advantage of engine decompression retarders and exhaust brakes over hydraulic and squid-type retarders is that the former retarders are bulky and expensive compared to the mechanisms required for conventional exhaust brakes or engine decompression retarders. This requires a dynamo or turbine device. A typical engine decompression II tarda is shown in U.S. Pat. No. 3,220,392 to Kumins, and an exhaust brake is shown in U.S. Pat.
It is disclosed in Japanese Patent No. 054,156. Another mechanism for providing compression damping is disclosed in U.S. Pat.
, No. 809,033, No. 3,786,792, No. 3.
No. 547.087, No. 5.859.970 and No. 3
, No. 357, No. 312.

For example, U.S. Patent No. 3,220,392 on cuminth.
Another advantage of an engine decompression retarder such as that shown in that publication is that it uses existing valve mechanisms and requires only the addition of a master piston and slave piston for each cylinder along with appropriate control systems. That's true.

The problem with using engine pulp or fuel injection pushers as a source of motion, such as occurs with Kuminme-type decompression retarders, is that the valve must be able to generate forces that are different from and possibly much stronger than those contemplated in the original engine design. As a result, damage to the injection push tube can result.

Furthermore, with this type of arrangement, the timing of the decompression operation is necessarily determined by valve operation that is not optimal for the deceleration function occurring elsewhere in the engine.

10- One way to solve the aforementioned problem of creating excessive stress in the valve mechanism VC is shown in U.S. Pat. No. 4,271,796, where a decompression device is incorporated into the hydraulic system to limit the maximum pressure that can be applied. The use of relief valves for this purpose is disclosed in US Pat. No. 4,150,640.

The inventors have demonstrated that by using hydraulic pulses generated by an actively driven hydraulic pulse generator in synchronization with the engine crankshaft, the inventors have improved (a) improved engine deceleration and b) engine valving. It has been found that complete prevention of the risk of damage can be achieved. More particularly, according to the invention, a crankshaft, an intake and exhaust manifold, at least one exhaust valve for each cylinder,
at least one slave piston for synchronously opening said exhaust valve during a braking operation; a rotary hydraulic pulse generator which is driven by a rotary hydraulic pulse generator to sequentially supply pulses of hydraulic fluid under pressure to predetermined slave pistons through a duct, said ducts interconnecting said slave pistons and said hydraulic pulse generators; a common valve control connected and disposed in association with said duct to establish low pressure fluid conditions in said duct during a fuel supply operation when said valve control is inoperative; A decompression engine retarder is provided which, when operated during braking, establishes high pressure fluid conditions in the duct.

A hydraulic pulse generator generates hydraulic pulses timed to coincide with the beginning of the expansion or power stroke of each cylinder in a four-stroke engine. This hydraulic pulse generator can be driven by a shaft operating at engine speed or at half engine speed. The timing can be adjusted over a wide range by varying the position of the pulse generator and its drive shaft relative to the engine crankshaft, and the magnitude of the pulses can be determined by the design of the pulse generator. Furthermore, the timing can be adjusted as a function of boost to more accurately control the decompression operation.

The objects and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings. The basic operation of decompression engine retarders is currently well known in the art and will therefore be described in detail herein. There's no need. However, simply put, a decompression retarder uses the movement of a member in a valve mechanism or fuel injection mechanism, typically a push tube, in close proximity to the desired timing.

And this movement is used to drive the master piston.

The master piston is hydraulically interconnected with a slave piston that, during braking, activates the exhaust valve (or dual exhaust valve) at or near the beginning of the expansion or power stroke of the four-stroke engine. It acts to open up. If the decompression engine retarder is activated, since this is a braking operation, the fuel supply is automatically cut off and the engine supplies only air. By releasing the exhaust valve at the beginning of the engine's expansion or "power" stroke.

The work done to compress the air during the compression stroke is not recovered during the expansion stroke, but rather is dissipated through the engine exhaust system and cooling system.

The energy absorbed by the engine can be measured by an electric dynamometer as the number of decelerating horsepower produced by the engine. Of course, the total deceleration effect includes the energy losses exhibited by the internal friction of the engine and all other losses associated with engine appurtenances. The absolute value of the reduced horsepower number produced during decompression deceleration is a substantial portion of the positive horsepower number produced by the engine during normal refueling operations.

The following will explain the 8g1 diagram showing the movement of the exhaust valve of Yuzu. In FIG. 1, exhaust valve motion is plotted on the vertical axis and crank angle starting at top dead center (TDC) is plotted on the horizontal axis. Curve 10 is.

Figure 3 shows the normal operating pattern of the exhaust valve at the beginning of the engine's exhaust stroke. Curve 12 shows typical exhaust valve motion for an engine with a compression brake designed to open the exhaust valve as close as possible to top dead center at the beginning of the engine's expansion stroke. More specifically, curve 12Fi shows the movement of the exhaust valve imparted by the fuel injection pusher.

The motion represented by curve 12 can be produced, for example, by the apparatus described in the above-mentioned U.S. Pat. curve 16
represents the desired optimal movement of the exhaust valve to maximize the dissipation of the power stored in the engine during the compression stroke. It will be appreciated that the precise timing at which the decompression exhaust valve opens should be selected to maximize the work of compression and minimize the total recovery of that work during the subsequent expansion stroke. This means that this valve opens rapidly near the end of the compression stroke and near the top dead center position 1k.

However, it is not possible to obtain optimal operation of the decompression mechanism if the valve actuation movement originates from other parts of the engine, such as the fuel injection pusher or the exhaust pusher for other cylinders.

The second figure is, for example, the piston pump 18 in figure 2fl1.
1 is a graph of volume versus time for a positive displacement pulse generator such as; The pump 18 includes a shaft 20 driving a crank 22 which drives a connecting rod 24 (established in the piston 26), the piston 26 being constrained to move within the cylinder 28. It will be observed that the displacement curve 3001 is similar to the optimal valve travel curve 16 of FIG. 1. The portion of the displacement curve 3001, eg, the portion above line 32, therefore acts as a valve actuation pulse if properly timed.

The operation of a decompression engine retarder according to the invention using a six-unit pulse generator is then illustrated in the third section.
- Figures 36 will be explained.

Engine block km for a 6-cylinder 4-stroke internal combustion engine
A fragmentary portion is indicated by reference numeral 64. The cylinder 461 is designated by the reference numeral 66 and contains the piston 38.
166 is designated by reference numeral 40 and contains a piston 42 . In the particular engine shown, the pistons for cylinders 1 and 2 simultaneously reach top dead center (1'DC) and move in unison. However, the piston, 461 (
38) moves upward during the exhaust stroke, the piston,
466 (42) moves upward during the compression stroke. It will be appreciated that cylinders 2 and 5 and cylinders 3 and 4 are similar pairs. Although the operation of the present invention will be described in terms of sequential operation with respect to cylinders 1 and 6, it will be appreciated that similar operation may occur at different times with respect to the other cylinders.

The intake valve 44 for cylinder %1 (36) is normally biased to a closed position by a valve spring 46. Similarly, the intake valve 48 for the cylinder, 466 (40), is also biased into the closed position by the valve spring 50. Suction valve 44.4
6 can be actuated by a swinging arm (not shown).

Exhaust valve 52 for cylinder, %1 (36) is 17- It is held in its closed position by the valve spring 54.

The exhaust valve 52 is opened during the refueling cycle of engine operation by a swing arm 56 driven by an engine cam J11f (not shown) and acts through a crosshead 58. A subordinate piston 6[1 is mounted for reciprocating movement within a subordinate piston cylinder 62, which cylinder is formed in a housing 64 fixed to an engine head 63, which is fixed to the engine block 34.

The slave piston 60 is biased away from the crosshead 58 by a spring 65.

Similarly, exhaust valve 66 for cylinder 466 (40)
is also biased to its closed position by valve spring 68. The exhaust valve 66 is opened by a swinging arm 70 acting through a crosshead 72 during a refueling cycle. A slave piston 74 is mounted for reciprocating motion in a slave piston cylinder 76 formed within the nozzle housing 64. The slave piston 74 is biased away from the crosshead 72 by a spring 78.

The duct 80 communicates between the slave piston cylinder 62 , 76 formed in the housing 84 of the pulse generator 85 and the master cylinder 82 . Master cylinder 82
Disposed within the housing 64 radially to a Fi pulse generator drive shaft 86, which can be any engine accessory or auxiliary drive shaft, operates at engine speed and is directly driven by the engine crankshaft. Actively or indirectly driven to maintain synchronization with the engine crankshaft.

Master cylinders 88 and 9041 are radially disposed relative to drive shaft 86 and are connected to each other and master cylinder 82.
120 arcs apart. Duct 92 runs from master cylinder 88 to slave piston cylinder (not shown).
These slave piston cylinders are identical to slave piston cylinders 62 and 76, but are interlocked with engine cylinders 2 and 5. Similarly, duct 9
4 is a slave piston cylinder C from the master cylinder 90
These slave piston cylinders are identical to the slave piston cylinders 62 and 76, but are interlocked with the engine cylinders 463 and 4.

The eccentric 96 is fixed to the drive 1qlI8B which is driven counterclockwise as shown in Figure 3^-3 [F].

Rotation of the drive shaft 86 drives an eccentric 96 against a ring 97, said ring 97 being connected to the master cylinder 82.88.
The master pistons 98 and 90 reciprocate in contact with mounted master pistons 100 and 102, respectively, to sequentially move the pistons radially outwardly from the drive shaft 86. The master piston 98.10 [1
The motion imparted to and 102 is functionally equivalent to the motion produced by the slider crank mechanism shown in FIGS. 2(3) and 20. Details regarding the structure of the pulse generator 85 are described below with reference to FIGS. 4 and 5.0 With reference to FIG. 3(2), the piston 3 of the cylinder 461
8 starts moving upward during the exhaust stroke, cylinder /I6
The second piston 42 starts moving upward during the compression stroke. Ring 97, driven by eccentric 96, also begins to move master piston 98 radially outward. At this point, exhaust valves 52 and 66d are still closed, and master piston 9 has moved sufficiently to bring duct 80 and the hydraulic fluid contained therein under low pressure hydraulic pressure within eccentric chamber 104 of the pulse generator. Isolate from fluid supply. This is the third
The L-shaped passageway 106 in the master piston 98 which is shown in the figure and communicates the duct 80 with the eccentric chamber 104 when the master piston 88 is in the radially inward position is in this case
It does not communicate with the eccentric chamber 104.

Figure 31BI shows the compression at a time slightly delayed from the time when the swinging arm 56 opens the exhaust valve 52 in the normal force valve opening order required for the normal exhaust stroke of the cylinder 61 (36). The release mechanism is shown. When the exhaust valve 52 and its crosshead 58 are displaced downwardly, the movement of the slave piston 60 is restrained only by the deflection of the spring 65. As a result, as the pressure in duct 80 increases due to the radially outward movement of master piston 98 , hydraulic fluid flows into slave cylinder 62 and contacts 108 on slave piston 60 are attached to housing 64 . The slave piston 60 is driven downward until it abuts the stop 110. The movement of the slave piston 60 that occurs while the hydraulic fluid in the duct 80 is still at a relatively low pressure has no effect on the exhaust valve 52 controlled by the rocking arm 56 during this time. will be understood. duct 80
As soon as the pressure within slave piston cylinder 62 becomes high enough to overcome the bias of spring 65 in slave piston cylinder 62, it also overcomes the bias of spring 78 in slave piston 76 and forces slave piston 74 into crosshead 72. Let me come into contact with you.

This closes off the clearance that normally exists between each subordinate piston and its associated exhaust valve when the duct 80 is in communication with the low pressure present in the eccentric chamber 104. However, the exhaust valve 66 is not opened when the slave piston 74 is reached. This is because the force required to open valve 66 is much greater than the force required to move slave piston 74 against the bias of spring 78, so that only movement of slave piston 74 occurs.

FIG. 30 shows the decompression mechanism when master piston 98 has reached its maximum stroke.

At this point, the hydraulic pressure in the duct 80 has reached a high level and the compressed air in the cylinder, 46 (40) is sufficient to overcome the bias of the valve spring 68 and the force on the valve 66, causing the exhaust valve 66 is released. It will be appreciated that the movement of the master piston 98 is controlled by the position of the eccentric 96 and the exhaust valve 66 is opened proximate the TDC position of the piston 42 to maximize the retardation horsepower produced by the engine. This means that the maximum amount of work is done in compressing the air during the compression stroke.

and ensures that a minimal portion of this work is pressure recovered during the subsequent expansion stroke.

Figure 3a shows the mechanism in which the eccentric 96 has been moved until the master piston 98 has been substantially retracted to the position shown in Figure 50. As a result of the retraction of master piston 98, the pressure in slave cylinder 76 is
Valve spring 68 drops to the point where it closes valve 66. meanwhile.

The swing arm 56 swings back to its initial position and the valve spring 54 closes the exhaust valve 52.

When the exhaust valve 52 closes, the slave piston 60 is driven upward. It will be seen that the axis 86 has moved by an angle slightly less than 90 DEG, as indicated by the arcuate motion of dashed line 112 between FIGS. 3 and 30. Then, upon movement of the drive shaft approximately 30 degrees, the master piston 98 is retracted, causing the duct 80 to communicate with the eccentric chamber 104 through the L-shaped passage 106, thereby reducing the pressure within the duct 80 and the eccentric chamber 104. balance the pressure of Under these conditions, the bias of springs 65 and 78
0 and 74 away from crossheads 58 and 72, respectively. As can be seen from the position of dashed line 112 in FIG. Therefore the cylinder, 46
Start the operation cycle of the cylinder, 1 and 2 in the same manner as described above for 1 and 2. Subsequent rotation of the pulse generator drive shaft 86 then causes the cylinder/163 >
and 4 r (reverse these cycle movements as a result of the movement of the master piston 102.

FIG. 30 shows the state of the decompression mechanism when the eccentric 96 reaches the master piston 98. At this point, cylinder %6(401) begins its exhaust stroke and cylinder %61(36)Fj:.

The compression process has begun. In these conditions,
The swinging arm 70 swings downward against the crosshead 72 to open the exhaust valve 66.

Thereafter, as the pressure within the duct 80 begins to rise, hydraulic fluid flows into the slave cylinder 76 and forces the slave piston 74 so that the contact 114 on the slave piston 74 hits the stop 25-116 mounted on the housing 64. Move it downward until it touches. As mentioned above, hydraulic fluid again flows into the slave cylinder 62 to move the slave piston 60 downwardly until it contacts the crosshead 58.

3rd (1!'1) is almost the same as the above-mentioned FIG. 3C1, but the master piston 90 is
This state occurs near the top dead center ('rDc) position. Continued rotation of the pulse generator drive shaft 86 reduces the pressure within the duct 80 causing the exhaust valve 52 to close and eventually return the slave pistons 60 and 74 to their rest positions. This operating sequence is repeated for cylinder bodies 2 and 5 as well as cylinder skins 3 and 4.

During two revolutions of the pulse generator drive shaft 86, corresponding to two revolutions of the engine crankshaft, each of the engine cylinders undergoes a decompression movement near the end of the compression stroke and near the top dead center position of the piston.

Next, explanation will be given on Figure 4 (Al and 4a31) showing an enlarged view of the pulse generator shown in Figure 3 and Figure 3 [F]. Figures 4 (A) and 4a3 also show the timing advance mechanism and the pressure It has a release mechanism, an electromagnetic switch that controls the pulse generator, and other master piston structures. The pulse generator 85 consists of a housing 84 containing an eccentric chamber 104, the master cylinders 82, 88 and 90 are
They are spaced 120 radially apart around the circumference of the ventricle 104 . The duct 118 guides a low pressure hydraulic fluid, for example oil, to the eccentric chamber 104 and then through the master cylinders 82.88 and 90 in the duct 80 and slave cylinder 62.761. Similarly, the hydraulic fluid is guided to the duct 92.94 and its corresponding slave cylinder.

The operation of the pulse generator 85 is controlled by a solenoid valve 120, which consists of a single magnet coil 122, an armature disk 124, a control rod 126, and a ball valve 128 seated in a valve seat 130. The ball chamber 132 communicates with a drain (not shown). Beyond the ball valve 1130 are seven passages 136, 138, in which a disc valve chamber 134 is located.
140 extend from disc valve chamber 134 to master cylinders 82, 88, and 90, respectively. disc valve 1
42 is movably positioned within the disc valve chamber 134. When the solenoid valve 120 is completely disposed as shown in the fourth drawing, the armature disk 124 is released from the coil 122, and the control rod 126 and ball valve 128 are moved to the right (as shown in the fourth drawing (A1)). movement, causing hydraulic fluid from the disc valve chamber 134 to drain from the housing 85.

This action moves disc valve 142 to the right so that disc valve chamber 134 acts as a manifold with respect to passageways 136, 138 and 140. When the disc valve 142 opens, the master pistons 98, 10
It will be appreciated that the hydraulic fluid pumped sequentially by 0 and 102 returns to the eccentric chamber 104. It will be appreciated that when one master piston is pumping, the other two master pistons (and their associated passageways) are draining.

However, when the solenoid valve is energized (as shown in FIG. 41 [3)), the solenoid ball valve 128 is seated on the seat 132 due to the movement of the control rod 126 and the armature disk 124;
Pressure concentrates at disc valve 142 sealing off the low pressure passage. When eccentric 96 drives master piston 98 as shown in FIG. 40, high pressure from passage 136 causes disc valve 142 to seal off low pressure passages 138 and 140. This then causes high pressure hydraulic fluid to flow into the duct 8.
0 to perform the functions described above.

As shown in Figure 4 and Figure 4(B), the master pistons 98, 100, and 102 each have three parts;
namely, a cylindrical outer shell 144 and an inner sliding piston 146.
and a snap ring 148, which limits relative sliding movement between the inner piston 146 and the cylindrical shell 144.

Eccentric 96 and ring 97 first sealingly secure piston 14629- to cylindrical shell 144 and then move these portions of master piston 98 (or 100, 102) radially outwardly to open duct 80 ( or 92
．． It will be appreciated that Figures 4 and 4 (#3) further show the pressure control mechanism 150 inserted into the duct 80.

It will be appreciated that the corresponding ducts 92 reaching the cylinders 2 and 5 and the duct 94 reaching the cylinders /163 and 4 can also be provided with similar arrangements. The pressure control mechanism 150 includes a housing 152 containing a diametrical passageway 154 that communicates with a duct 80 and with an axial passageway 156 terminating in a cylindrical chamber 158 . A piston 160 is mounted for reciprocating movement within a cylindrical chamber 158 of the housing 152 and is connected to the axial passageway 156 by a relatively stiff spring 162.
bias in the direction of Spring 162 and piston 160 are held in place by a cap 164 threaded onto housing 152.

In operation, the pressure control mechanism 150 acts as a shock absorber, limiting the maximum pressure that can be generated by the pulse generation mechanism 85 by increasing the total volume of the hydraulic circuit when the pressure exceeds a predetermined level. . As will be understood by those skilled in the art, when the hydraulic circuit is relatively short, the bulk modulus of the hydraulic fluid is such that the fluid can be considered to be substantially incompressible, and some form It is desirable that the pressure control mechanism relieves excess pressure in the system. However, if the hydraulic path is relatively long, the compressibility of the hydraulic fluid is sufficient to effectively form its own expansion chamber. Instead of the pressure control mechanism described above, other devices can also be used, such as, for example, a Boulton tube mechanism that expands with pressure. In any case, whether or not a specific pressure control mechanism is used, the ducts 80°92 and 94
Care must be taken that the cylinders have approximately the same length and contain approximately the same amount of hydraulic fluid so that the action in each dependent cylinder is the same.

Additionally, the pulse generator 85 includes a timing advance mechanism that allows the timing of the hydraulic pressure pulses to be varied as a function of the pressure boost generated by the engine turbocharger (if the engine is equipped with one). It will be appreciated that the pressure build-up in the engine inlet manifold varies with the turbocharger series and that the amount of air introduced into the engine is also a function of the pressure build-up. Additionally, the pressure developed within the engine cylinder during the engine's compression stroke varies with the amount of air introduced into the cylinder during the engine's intake stroke, and the force required to open the exhaust valve is is a function of the pressure within the engine cylinders.

FIG. 6 shows a family of curves plotting the force required to open the engine exhaust valve on the vertical axis and the crank angle on the horizontal axis. Curve 166 shows how this force varies with crank angle at low boosts;
Curve 168II'i also shows a similar curve for high boosts. It will be appreciated that the engine may be operated at various pressure increases within the range shown by curves 166 and 168.

If it is desired to begin opening the exhaust valve at a particular point, say 15° B, T, D, C, to maximize the decompression deceleration effect, the master piston Y98 (straddle 100°.
It will be appreciated that the initial movement must precede this point. The slope of line 170 is
The pressure in the hydraulic system (e.g. duct) 80.92 and 94 rises as a function of time (or crank angle) during a low pressure increase to obtain the force required to open the exhaust valve as shown at point 172. Shows the speed for. line 170
The intersection of and the axis (point 174) is.

The crank angle at which master piston movement begins at point 172 is shown to open the exhaust valve.

Similarly, point 176 on the high pressure rise curve 168 shows the force required to open the exhaust valve at 15 B, T, 1), C under high pressure rise conditions. To obtain this force, the pressure in the hydraulic system increases along curve 35-178 and intersects the axis at point 180. As can be seen from FIG. 6, it is desirable to have a mechanism that automatically adjusts the timing of movement of the master piston in response to pressure increase.

This type of mechanism is shown in Figure 4 and Figure 40.

A boss 182 integrally formed with the housing 84 includes a cylindrical bore 184 that communicates at one end with a duct 18 through a passageway 186, the duct 188 communicating with an engine intake manifold (not shown). . This intake manifold is always subject to a pressurization created by an engine turbocharger (not shown). The piston 190 is inserted into the cylindrical hole 18
4 and biased toward the passageway 18 by a spring 192. Attach the trilobal cam 194 to the drive shaft 86,
It is possible to rotate independently of the eccentric 96 and the ring 97. The cam 194 is axially offset from the eccentric 96 so that the six pieces of the cam 194 engage the pistons 98, 100.
or 1020 sliding cylinder shell in one 14.4 K
contact but not the internal sliding piston 146. Joint 196tj interconnects cam 194 and piston 190.

At low pressurization, the piston 190 moves to the left (fourth (A)
1), thereby causing the cam 194 to rotate counterclockwise to the point where the cylindrical shells 144 of the pistons 98, 100, and 102 are driven radially outwardly from the drive shaft 86. As shown in FIG. 4a, upon high pressure increase, the piston 190 is driven to the right and the cam 194 rotates clockwise. This rotation of the cam 194 causes the piston 98
, 100 and 102, the cylindrical outer shell 144 is 114t18
6, allowing for radial inward movement in the direction of 6.

The movement of the cylindrical shell 144 is controlled by the master piston 98, 100i relative to the drive shaft 86. and 102 inward, and this motion is synchronized with the engine crankshaft. Thus, the timing of the movement of the master piston is a function of the external pressure. As a result, the exhaust valve is activated at a given point in time (e.g. 15B, I', In 1) and C), it is opened during the compression release deceleration operation.

Referring now to FIG. 5, another embodiment of the present invention will be described for use with a pulse generator drive shaft 86' operating at half engine crankshaft speed. In FIG. 5, parts common to FIGS. 3 and 4 are designated by the same reference numerals, and modified parts are designated with a prime "'".

The housing 84' includes six master cylinders 198, 2 for controlling the opening of exhaust valves for cylinders 46, 2, 4, 1.5 and 3, respectively, during decompression operations.
It contains 00, 202, 204, 206 and hi 20th. Master cylinder 198°200, 202
, 204, 206 and 208 are arranged in the same order as the engine firing order. Passage 210°212, 21
6, 218 and 220 communicate between the master cylinders 198, 200, 202, 204, 206 and 208, respectively, and six ball check valve chambers, only three of which are designated as chambers 222, 226 and 230. Illustrated. The other three ball check valve members are located behind chambers 222, 226 and 230, respectively, and are therefore not visible in FIG. Each ball check valve chamber is equipped with a seat 234, a ball check valve 236, and a spring 238 that normally biases the ball check valve 236. , each of the six ball check valve chambers communicates with the armature manifold chamber 240 through six passages, only three of which are connected to the armature manifold chamber 240.
2, 246 and 250. The other three passages are located behind passages 242, 246b and 250, respectively, and are therefore not visible in FIG. Armature 2
54 is disposed within the armature manifold chamber 240.

Hydraulic fluid passage 256 communicates between armature manifold chamber 240 and duct 258 to supply hydraulic fluid to pulse generator 85'. The electromagnetic coil is designated by reference numeral 260, and the +7-domain for the electromagnetic coil is designated by reference numeral 262, 2.
64. A relatively stiff spring 266 is seated in a hole 268 formed in the electromagnetic core, which normally biases the armature 254 away from the coil 260. Control rod 270 is connected to armature 254 and passageways 242, 246 and 2
50 and 357 located between the pole check valve 236 in one invisible passage.

Master pistons 272, 274, 276, 27
8.

280 and 282 as master cylinders 198, 20
0.

202, 20. i, 206 and 208, and these are connected to the drive shaft 8 by means of a ring 97 and an eccentric 96.
Move it from 6'. Duct 284#-1: Provides communication between the master cylinder 198 and a subordinate cylinder (not shown) that is linked to the engine cylinder rotor 6.

Ducts 286, 288, 290, 292, 29
4 communicate with engine cylinders 42, 4, 1.5 and slave cylinders (not shown) that are linked to engine cylinders 3, respectively. The pressure control mechanism 150 is connected to the ducts 284 and 286 in the same manner as described in connection with Figures 4 and 4 (B1).

290, 292 and 294, respectively. A circular cam 296 is attached to the shaft 86 adjacent to the cam 96.
' and can be fixed to, but rotatable about, this shaft 86'. In any case, cam 2
96 is the master piston 272°274, 276,
278, 280 and 282.

The operation of the mechanism shown in FIG. 5 is as follows.

When the electromagnetic coil 260 is de-energized (as shown in FIG. 5).

Pall check valve 236 remains open. the result,
each cylinder 198 , 200 , 202 , 204 .

Pistons 272, 274 at 206 and 208
.

The sequential movement of 276 , 278 , 280 and 282 directs hydraulic fluid into passageways 210 , 212 , '214
, 216 , 218 and 220 and N machine manifold chamber 240 into the master cylinder;
Ducts 284, 286, 288, 290, 29
2 and 294 resulting in little pressure rise. Chamber 240 ducts 2BA, 286, 29
0, 292 and 294 and the master cylinders respectively associated with these ducts act as a manifold. This system is filled with hydraulic fluid because leakage of fluid through the solid master pistons 272 , 274 , 276 , 278 , 280 and 282 into the eccentric chamber 104 is caused by the supply duct 258 This is because it is compensated for by Connect the drainage path (not shown) to the eccentric chamber 1.
04 to a hydraulic fluid reservoir (not shown).

However, when electromagnetic coil 260 is energized, armature 254 is attracted to coil 260 against the biasing force of spring 268, resulting in check valve 236 seating against seat 264. Passages 210, 212, 214, 216°21
When 8 o and 220 are closed, the piston 272°274
, 276 , 278 , 280 and 282 , respectively.
290.

292 and 294 in order to generate pressure caballus,
These pulses cause the engine cylinder,%6,
2. ! , i, 5 and 3 to operate the slave piston. The exact timing of the pressure caballus is determined by the drive a86.
It will be appreciated that this depends on the relative positions of the eccentric 9 and the eccentric 9. Since shaft 86' is driven at half engine speed, one revolution of shaft 86' generates one pulse in each cylinder of the engine when that cylinder is near the end of its compression stroke. If it is desired to vary the timing of the pressure pulses as a function of pressure increase, a fourth
^ and 6 with the same shape as the three-leaf cam 194 shown in Figure 40.
Leaves can be provided. The cam 2960 position is the 4th ■
and 4f3) controlled by a piston and coupling n7 responsive to pressure increase as shown in the figure. in this case.

Of course, the cam 296 needs to be rotatable about the shaft 86'.

Modified crossheads, such as those disclosed in U.S. Pat. No. 4,399,787 and South Akrika Patent No. 8,077,495, may also be used to open the exhaust valve during braking.

An alternative pulse generator 376 using a positive displacement gear pump will now be described with reference to FIGS. 7 and 8. When applied to an engine with 6 cylinders, this pulse generator 376#'i has 6 teeth and is designed to mesh with a 5-tooth gear 378 mounted eccentrically. Equipped with Gear 380 Fi,
It is journalled on an eccentric 382 fixed to a shaft 384 which is positively driven at half engine speed. Further, in detail.

41- Spline ring 3 day 6 (tlE 8 figure) to axis 384
At the same time, the washer 388 and cap screw 3
, -390 and fix it to the shaft. This spline ring 386 is positively driven at half the speed of the engine crankshaft and engages internal splines formed in the stone auxiliary drive shaft 392. If other accessories are to be driven by this auxiliary drive shaft 392, a ta2 spline ring 394 can be secured to the opposite end of the shaft 384.

The main body of the pulse generator includes an adapter plate 396, a main housing 398 secured to the engine block (not shown) by cap screws 466, and an extraction housing 40.
0. The rear housing 400, internal gear member 378, and main housing 398 are fixed together with one 402 to six caps located between the six lobes or roots of the teeth of the internal gear 378. An annular groove 404 is formed within rear housing 400.

This groove is connected to the hydraulic fluid supply duct 4 via the passage 406.
Connects to 08. The annular groove 404 has a maximum diameter smaller than a circle tangential to the rope of the internal gear 378, and the external gear 380 is connected to the internal gear 3.
As gear 380 rotates within 78 , it traverses annular groove 404 and introduces hydraulic fluid into the chamber defined by the teeth of gears 378 , 380 and the surfaces of housings 398 , 400 . The diameter of annular groove 404 defines the volume of chamber 410 and the point at which hydraulic fluid can be pressurized. The diameter of annular groove 404 thus defines the location of line 62 in the second diagram. An annular groove 4 whose dimensions are equal to the groove 404
12 is formed within housing 398. 〇-Ring 41
4, 416 to internal gear 378 and housing 4
00, 398 to prevent leakage of hydraulic fluid. A passage 418 is inserted between the internal gear 3 and the housing 398.
78 adjacent to the base of each of the six teeth. Passage 418 connects main housing 398 and adapter plate 396
This adapter plate acts as a manifold for the passage 418 and the several chambers 410 of the positive displacement gear pump. An annular manifold chamber 420 includes O-rings 422 and 42 located between adapter plate 396 and main housing 398.
4 can be used for convenient sealing. , an annular ring valve 426 is freely positioned within the annular chamber 420 and biased toward the housing 398 by a plurality of springs 428 seated in blind holes 430 formed in the adapter plate 396 .

A passageway 432 communicates between the annular chamber 420 and a ball valve chamber 434 (FIG. 7) containing a ball valve 466. A passageway 438 connects the ball valve chamber 434 and the supply passage 440 and connects the solenoid valve 442 to the adapter plate. This solenoid valve is attached to the solenoid coil 444.

A core 446 , a disk-shaped member 448 loosely mounted within an armature chamber 450 , and a pin 45 located within the core 446 between the armature 448 and the ball valve 436 .
It consists of 2.

When electromagnetic coil 444 is energized, armature 448
52 is moved against ball valve 436 to direct hydraulic fluid flow from passage 432 to passage 438 and then to supply passage 440.
prevent it from flowing.

Further, an outlet duct 454 is provided in communication with each passageway A18, the duct being connected to a mounting portion 456 within the main housing 398.
extends up to Mounting part 456 Fi each duct 28
4, 286, 288, 290, 292 and 2
94) (FIG. 5), these ducts are connected to subordinate cylinders which are respectively associated with cylinders A6, 2.4.1.5 and 3 of the engine.

A passageway 458 formed in the bottom of housing 400 connects tube 460 and passageway 46 formed in adapter plate 698.
It communicates with 4. Tube 460 can be conveniently sealed into housing 400 and adapter plate 396 by o-ring 462.

In operation, rotation of auxiliary drive shaft 392 drives shaft 384 and eccentric 382 to rotate five-tooth external gear 380 within six-tooth internal gear 378 . Pulses of hydraulic fluid are sequentially provided from each of chambers 410 through passageway 418 into annular chamber 420 . Some of the hydraulic fluid enters chamber 4 via passageway 418.
10 and annular manifold chamber 420, while a portion of the hydraulic fluid passes through passages 432 and 438 to supply passage 440 (see FIG. 7). Leakage t″L from chamber 410 along axis 384 and obtain fluid through passageway 458
and returns to the engine hydraulic fluid reservoir via tube 460 and passageway 464. Since the passage 432 is open when the solenoid valve is de-energized, no significant pressure can be created in the outlet duct 454.

However, when solenoid valve 442 is energized, it seals ball valve 436 passageway 432 and allows pressure to increase in annular manifold chamber 420 . This pressure seats the ring valve 426 in the passageway 418 under low pressure, and the pulse of hydraulic fluid from the chamber 410 pressurizes the passageway 418 and the outlet duct 454, causing the ducts 284, 286
, 288, 290, 292 or 294 and its associated dependent cylinders. Continuous rotation of the auxiliary drive shaft 392 is achieved through the ducts 284 and 286.
, 288 , 290 .

Pulses of hydraulic fluid are sequentially applied to each of 292 and 294 and their associated dependent cylinders.

When the auxiliary drive shaft 392 rotates at half the speed of the engine crankshaft, one hydraulic pulse is generated in the ducts 284 , 286 , 288 , 2 during two revolutions of the engine crankshaft.
90, 292 and 294 and their associated slave cylinders. By appropriately adjusting the spline ring 386 relative to the auxiliary drive shaft 392, each engine exhaust valve adjusts the T and D of the engine piston at the end of the compression stroke of the associated cylinder.
, the pulse can be timed to open at a predetermined time proximate to the C position.

The above explanation assumes the use of a 6-cylinder engine, but
The pulse generator explained in Figures 7 and 8 has been modified! By providing an internal gear 378 having the same number of teeth as the number of cylinders in the engine and an external gear 380 having one fewer tooth than the number of cylinders in the engine, an engine having an arbitrary number of cylinders can be created. This can be applied to this book.

The pulse generator of FIGS. 7 and 8 includes one chamber 410 for each engine cylinder. If desired, only three chambers can be used according to the subordinate cylinder arrangement shown in FIG. In this case, the outlet 456 of the other chamber 410 is connected to the supply path 408 or 44.
0 or other chamber 410 outlets could be used for other purposes. Of course, the pulse generator of FIGS. 7 and 8 could also be designed with one chamber 410 for every six pairs of engine cylinders. Similarly, the pulse generator of Figure 5 was modified to provide the engine with one master piston for six pairs of cylinders, and the pulse generator of Figures 3 and 4 was modified to provide one master piston for each engine cylinder. A master piston can also be provided.

Although neither the pressure control mechanism nor the boost timing mechanism is shown in FIGS. 7 and 8, it is understood that either or both of these mechanisms could be used in the embodiment of FIGS. 7 and 8. It will be obvious to business owners. A duct 80, 92 or 94 or a duct 284, 286, 288, 290 or 1 connecting the pressure control mechanism 150 shown in Figures 4 and 4 between the outlet 456 and the slave cylinder.
It can be installed on i294. The step-up timing mechanism is the seventh
For incorporation into the embodiment of FIGS. and 8, the drive shaft 38
It is necessary to swing the internal gear 378 with respect to 4. This is the cap screw 40
2 is formed as an arc-shaped slot, and the hydraulic cylinder 184° 190 and the coupling portion 196 are provided as shown in Figure 4 and Figure 4a1, and the gear 378 is configured to respond to changes in the external pressure of the suction manifold. This can be achieved by rocking.

[Brief explanation of the drawing]

Figure 1 is a graph of exhaust valve movement during each cycle of engine operation, and Figure 2 is a graph of positive displacement pulse generator displacement as a function of time. Figure 49-g21BI is a schematic illustration of a positive displacement pulse generator in the form of a crank-driven piston and cylinder. Figure 3 is a diagram of a decompression engine retarder with three units of pulse generators operating at engine speed, each unit controlling the exhaust valves of two cylinders in a six-cylinder engine to initiate braking action for cylinder/166. 30 is suitable for alternately opening the mechanism at the initial stage of the pulse when the dependent piston of the cylinder shoulder 1 is seated on the stop; is an explanatory diagram showing the mechanism in Fig. 3 (8) at the maximum pulse pressure when the slave piston for cylinder /I6 opens the exhaust valve of cylinder /I6, and Fig. 30 is an explanatory diagram showing the mechanism of Fig. 50-3D is an explanatory diagram showing the mechanism of the third (A1) when the dependent pistons for cylinders 161 and 6 have returned to the reset position, and FIG. It is an explanatory view showing the mechanism of Fig. 3 in the initial stage of continuous pulse pressure for
It is an explanatory diagram showing the mechanism of the third drawing at the maximum pulse pressure when the exhaust valve of Xun 1 is opened. FIG. 3 is an enlarged view of the pulse generator showing details. Figure 41B) is an enlarged view of the pulse generator showing the solenoid valve in the energized position and the timing advance mechanism in the high boost position. FIG. 5 is an enlarged view of an alternative six-unit pulse generator designed to operate at half engine speed and with solid pistons, check valves, and overtravel mechanism; FIG. FIG. 8 is a graph showing the effect of turbocharger boost on the timing of FIG. It is a sectional view taken along line 8. 10.12・, song m 16 river 1ttl line 1
8... Bump 20... Shaft 22...
・Crank 24...Connection rod 26...Piston 28...Cylinder 30...Curve 32...
・Line 34...Engine block 36...Cylinder 38...Piston 40...Cylinder 42
...Piston 44...Valve 46...Spring 48...Valve 50...Spring 52...Valve 54...Spring 56...Arm 58...
・Cross head 60...Vis ton 62...
Cylinder 63 Crosshead 64...Housing 65...Spring 66...Valve 68
...Spring 70...Arm 72...
Head 74...Piston 76...Cylinder 78...Spring 80...Dat 82...
・Cylinder 84...Housing 85...Pulse generator 86...Drive shaft 88.90...Cylinder 92.94...Duct 96...Eccentricity
Container 97... Ring 98.100,1
02...Piston 104...Eccentric chamber 106...
Passage 108...Contact part 110...Stop
Stop part 112...Dotted line 114...
・Contact part 116...Stop part 11
8... Da Rito 120 River electromagnetic valve 122...
Electromagnetic coil 124... Armature disk 126...
Control rod 128...Ball valve 130...Valve
Seat 132...Ball room 134-1. Pulp chamber 1
36,138.140-...Passage 142...Disc valve 144...Cylindrical outer shell 146...Piston 1
48...Ring 150...Pressure control mechanism 15
2... Housing 154.156... Passage 15
8...Cylindrical chamber 160...Piston 162...
・Spring 164...Cap 166.168・
...Curve 170...Line 172.174.1
76...Point 178...Curve 180...Point 182...Boss 184 Hole part 186...
・Aisle 188...Da Rito 190...
Piston 192...Spring 194...Ka
Mu 196...Joint 198.200,202
,2071,206,208 ・y ring 210.21
2,216,218,220...Aisle 222...
・Chamber 226...Chamber 230...Chamber 234...Seat part 236...Check valve 23
8...Spring 240...Manihole)" Chamber 2A
2...Teyanba 246...Chamber 250.
...Chamber 254...Armature 256.
・Aisle 258 ・1. Da Rito 260... Coil 262.2
64...Lead 266...Spring 268...
・Core 270...Control rod 272.274
, 276.27B, 280.282... Piston 28
4.286,288,290,292,294...Digital 296...Cam 376...Pulse R=Raw D378,380...Gear 382
... Eccentric device 384 ... Shaft
386...Ring 388...
・Washer 390...Screw 392...Drive shaft 394...Ring 396...Adapter plate 398,400...Housing 402...Screw 404...Groove portion 406...Thread Road 408... Da Rito 41
0...Chamber 412...Groove portion, 1111.
416...0-ring 418...Passage 4
20...Annular chamber, 1122,424...
・0-ring 426...* 42B...Spring 430...Hole part 432...Thread
Channel 434...Chamber 436...Valve 438...
・Passage 440... Supply channel 442... Valve 444... Coil 446... Coil
A 448...Electrical element 450...
Chamber 452... Pin 454...
G 456... Mounting part 458... Passage 460... Tube 462... O-ring 464
... Passage 466 ... Screw Procedure Amendment (Voluntary January 20, 1980 Director General of the Patent Office Kazuo Wakasugi 1, Indication of the case 1981 Special Gate No. 229257 2, Name of the invention Multi-cylinder decompression engine retarder 3 for internal combustion engines;
Relationship with the case of the person making the amendment 4q - Patent applicant name Sajie Cobbs Manufacturing Company Representative Kenneth H. Sysokura φhikiichi) (United States of America) 4. Agent (1) Drawings. F/θ, l

Claims (1)

[Claims] (1) a crankshaft (86), an intake and exhaust manifold, and at least one exhaust valve for each cylinder;
a decompression engine retarder for use in a multi-cylinder four-stroke internal combustion engine, the decompression engine retarder for use in a multi-cylinder four-stroke internal combustion engine comprising at least one slave piston for synchronously opening the exhaust valve during deceleration operations; a rotary hydraulic pulse generator (85, 85') which is driven in a circular manner and supplies pulses of hydraulic fluid under pressure sequentially to predetermined subordinate pistons by means of a duct (80, 92, 943); ) (80, 92, 94) interconnect the slave piston and the hydraulic pulse generator and further include a common valve control (120) disposed in association with the duct.
) to establish a low pressure fluid condition in the duct when the valve control is inactive and which occurs during fuel supply operations. A decompression engine retarder characterized in that a valve control establishes high pressure fluid conditions in the duct when operated during deceleration. (21 duct has branches (136, 138) for connecting the duct to the drain when the valve control section is not operating.
, 140) or (210, 212, 214; 216, 218, 220), said branch being closed by said valve control during deceleration to prevent drainage of hydraulic fluid f2. 2. An engine retarder according to claim 1, wherein high pressure hydraulic fluid is transferred from the pulse generator through the duct to the slave piston. 131 Pressure control means (156), characterized in that the pressure control means (156) communicate with the duct and include a chamber that can expand in response to pressure to limit the maximum pressure produced by the pulse generator to a predetermined level. The engine retarder 6 (4) pressure control means recited in claim ia1 and claim 2 includes a duct (80, 92, 9a
) and a cylinder (152) communicating with this cylinder (11).
1. A piston (160) mounted in a cylinder for reciprocating movement; and a spring (162) for biasing said piston against the pressure of hydraulic fluid in said cylinder and duct. Engine retarder according to range 3. (5) The engine retarder according to claim 3, wherein the pressure control means comprises a Poulton tube. (l, 1) A rotary hydraulic pulse generator is driven at engine speed and includes one positive displacement pump member (85) for each pair of engine cylinders, said engine cylinders simultaneously An engine retarder according to claim 1, characterized in that the engine retarder comprises a piston that reaches top dead center of the engine. 2. A positive displacement pump member as claimed in claim 1, wherein the duct interconnects each positive displacement pump member and a slave piston for associated actuation of the exhaust valve. engine retarder. (81 positive displacement pump members each have a first cylinder (
a first piston (198) reciprocatable between a first position and a second position within the first piston (272);
The position is adjusted by the pressure adjusting means in response to the pressure in the intake manifold of the engine [7, the pressure adjusting means is the first
A rotary cam (194) that cooperates with the piston to define the first position of the first piston and communicates with the intake manifold via a second duct! 2 cylinders (182)
a second piston (190) capable of reciprocating within the second cylinder (1B2) in response to pressure in the second cylinder and the intake manifold; a spring (192) in said second cylinder biasing two pistons; 8. The engine retarder according to claim 6, further comprising a joint (196) interconnecting the second piston and the rotary cam. (9) The valve control section is the first one in the manifold (134).
Move between position and second position1. Vine first disc valve (
142) and a VTA-operated check valve (12B) communicating with the manifold, the manifold interconnecting each of the ducts, and the disc valve interconnecting each of the ducts in one of its plurality of positions. 9. An engine retarder as claimed in claim 8, in which scales prevent coupling but otherwise interconnect each said duct through said manifold to a drain. (10) The rotary hydraulic pulse generator comprises a positive displacement gear pump driven at half engine speed and having internal gears (378), said internal gears having a number equal to the number of cylinders in a multi-cylinder engine. The external gear (380) is provided with teeth or ropes and meshes with an external gear (380), and the external gear is one point smaller than the internal gear.
a number of positive displacement pump chambers (410) having fewer teeth and equal to the number of cylinders in the multi-cylinder engine; 2. The engine retarder of claim 1, wherein said duct interconnects each positive displacement pump chamber and a slave piston. (11) The control valve (442) is a ring valve (442) movable between a first position and a second position within the manifold (450).
48) and an electromagnetically actuated check valve (436) communicating with the manifold, the manifold interconnecting each duct, and the ring valve (4481 being the first
11. The duct according to claim 10, characterized in that in its second position it prevents interconnection of the ducts, but in its second position interconnects the ducts through the manifold to a drain. engine retarder.