JPH0311364Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention is used in engines where the exhaust valve is slightly opened during the compression process when the engine is used as an air compressor that absorbs power. This invention relates to an engine/brake operating device.

BACKGROUND TECHNOLOGY Today, in the case of engines mounted on large vehicles, when the engine can be used as an air compressor to absorb power, the compression stroke is In some systems, engine braking operating devices have been provided that slightly open the exhaust valves.

Such devices include, for example, engine brake operating devices disclosed in Japanese Patent Application Laid-open No. 49-57216 and Japanese Patent Application Laid-open No. 51-132343.

The former is configured to open and close the exhaust valve with a hydraulic mechanism attached to the exhaust rocker arm, while the latter is located between the cam shaft and push rod located within the cylinder block. Since the exhaust valve is configured to open and close with a hydraulic cylinder type tappet, in the former case, in connection with the valve opening/closing operation of the exhaust rocker arm, the exhaust valve is additionally slightly The mechanism for setting the opening/closing timing becomes complicated, and in the latter case, the fluid passage between the controller and the hydraulic tappet becomes long, which may cause a delay in operation.

Further, Japanese Patent Application Laid-Open No. 50-29906 discloses an engine device that also serves as an air compressor.
In this engine device, a cam is fixedly supported on a camshaft with an engine acting cam surface and a compressor acting cam surface, and the camshaft is moved in the axial direction by a shifter that is linked to a brake device, and the tappet is attached to the engine. Due to the selective abutment of the working cam surface and the compressor working cam surface, a large force is required to drive the shifter, where a cam switching device is used, and the cam is axially long. Therefore, in multi-cylinder engines, placement on the cylinder head becomes difficult.
In addition to making the layout extremely complicated, the camshaft bearing is able to slide back and forth in the axial direction to support the radial load, making the structure complex and the sprocket support structure also complicated. .

Furthermore, in this engine arrangement, the exhaust port is connected to a compressed air storage vessel, so the exhaust valve requires a means of closing to overcome the compressed air back pressure present in the exhaust pipe, and When operating an air compressor, a load reduction means was required to open the intake valve during startup and to maintain a constant pressure in the compressed air storage container, thereby reducing the load without causing the engine to act as a compressor. .

Purpose and problem of this invention The purpose and problem of this invention is to change the engine to an air compressor when using it as a braking means, and to make it possible to obtain sufficient exhaust braking force from the engine. An object of the present invention is to provide an engine brake operating device used in an engine.

Other purposes and issues of this invention are exhaust and
By means of a drive means independent of the push rod for the locking arm and its exhaust locking arm, in connection with the valve opening and closing movements of the exhaust locking arm, the exhaust valve can additionally be slightly moved. A part that opens and closes to enable the engine to be used as an exhaust brake means, in other words, as an air compressor that absorbs power, and in addition, makes it easy to set the timing for slightly opening and closing the exhaust valve. An object of the present invention is to provide an engine brake operating device for use in engines of the present invention.

Another purpose and problem of this invention is to miniaturize it so that it can be assembled on the cylinder head of the engine, in other words, it can be installed together on the cylinder head, and it is freed from operation delays caused by liquid passages. The purpose of the present invention is to provide an engine/brake operating device for use in an engine.

Summary of the invention related to the purpose/problem: Contents of the claimed invention In relation to the above-mentioned purpose/problem, the engine/brake operating device of this invention has the following features:
In connection with the valve opening/closing operation of an exhaust rocker arm swingably supported on the rocker arm shaft, an exhaust valve is mounted on the cylinder head independently of the rocker arm shaft to open and close the exhaust valve. an engine brake operating cam fixedly disposed on the exhaust brake cam shaft, corresponding to the exhaust valve thereof; A valve pushbutton located between the brake operating cams and attached to the valve stem of the exhaust valve.
a timing gear shaft disposed on the cylinder head and driven by the engine in conjunction with the engine brake cam shaft; The driven side is supported in a non-rotating manner so that the driven side can slide back and forth on the engine brake cam shaft, and the engine brake cam shaft is supported on the timing gear shaft.
It also includes a timing clutch that switches the cam shaft on and off.

Description of Specific Examples Specific examples of the engine/brake operating device of this invention will be described below with reference to the drawings.

Figures 1 and 2 are mounted on a truck and 4-
6- where each cylinder is equipped with a valve
10 shows a specific example 10 of an engine brake operating device applied to a diesel engine consisting of cylinders, and one cylinder selected from six cylinders each applied thereto. Of course,
In the cylinder of the diesel engine, two intake valves (not shown) and two exhaust valves 30, 31 are arranged, and the intake valves are grouped together by an intake crosshead (not shown). The valves are opened and closed by an intake rocker arm (not shown) that is swingably supported by a rocker arm shaft 36, and the exhaust valves 30 and 31 are connected to the exhaust crosshead 34
The valves are opened and closed by an exhaust rocker arm 37 that is swingably supported by a rocker arm shaft 36. These intake lock arm and exhaust lock arm 37 also need no explanation.
The engine's cylinder block (not shown)
A cam of a cam shaft (not shown) located in the rocker arm shaft 3 through a tappet (not shown) and push rod 38.
It is swung around 6.

The engine brake operating device 10 operates in conjunction with the valve opening/closing operation of the exhaust rocker arm 37 that is swingably supported on the rocker arm shaft 36.
A cylinder of the engine is mounted at a predetermined distance above the valve stem 32 of the exhaust valve 30 and is independent of the rocker arm shaft 36 to open and close the valve 30.
The engine brake camshaft 11 located on the head (not shown) and its exhaust valve 30 correspond to
An engine brake operating cam 12 fixedly disposed on the brake cam shaft 11 and a valve stem 32 of the exhaust valve 30 located between the engine brake operating cam 12 and the exhaust valve 30 thereof. a timing gear shaft 14 disposed on the cylinder head and driven by the engine in conjunction with the mounted valve push rod 13 and the engine brake camshaft 11; A clutch disk 22 is fixedly supported on the timing gear shaft 14, and a driven side clutch disk 23 is supported on the engine brake cam shaft 11 so as to be slidable back and forth so as not to rotate. - The gear shaft 14 includes a timing clutch 16 that connects and disconnects the engine brake cam shaft 11.

The engine brake cam shaft 11
is connected to the timing gear shaft 14, which has the timing gear 15 at one end, through the timing clutch 16 at the other end.

The engine, brake, camshaft 11
has a pilot (not shown) protruding from one end, and rotatably supports the pilot in a bore (not shown) opened at the other end of the timing gear shaft 14 via a bearing (not shown). I'm letting you do it.

Further, the engine brake cam shaft 11 has a number of splines 21 formed on the outer peripheral surface of one end for the timing clutch 16.

The timing gear shaft 14 is a crankshaft gear (not shown) fixed to a crankshaft (not shown) of the engine.
A gear (not shown) meshingly coupled to the idler gear (not shown) and its timing
It is connected to the crankshaft by a timing belt 17 wrapped around the gear 15, and is driven, that is, rotated, by power from the crankshaft.

The timing clutch 16 is constructed with a driving clutch disk 22 and a driven clutch disk 23 in a more meshed manner.

The drive side clutch disk 22 is fixed to the other end of the timing gear shaft 14;
Further, the driven side clutch disk 23 has a large number of spline grooves (not shown) formed in the bore 24 corresponding to the splines 21 of the engine brake cam shaft 11, and the splines 21 are inserted into the spline grooves. Make it correspond,
The bore 24 is connected to the engine, brake, cam,
It fits into the spline portion of the shaft 11 and is supported by the spline portion so as to be able to reciprocate and slide.

The driven clutch disc 23 is also engaged by the driving clutch disc 22 by a cranking and disengaging yoke 25 which is electromagnetically driven against a lease spring (not shown). Of course, the clutch release yoke 2
5 may be hydraulically or pneumatically driven.

The engine brake operating cam 12 is integrally formed with the engine brake cam shaft 11 at a predetermined location. Of course, the number of cams 12 corresponding to the number of cylinders is the same as that of the engine brake cam shaft 11.
It is machined by cutting.

Of course, the lobe (Iobe) of the cam is related to the valve opening and closing operations of the intake rocker arm and the exhaust rocker arm 37.
It is determined in advance in accordance with the valve lift that additionally and slightly opens and closes the exhaust valve 30.

Also shown in FIG. 2 are other engine brake operating cams 19, 20 integrally formed on the engine brake cam shaft 11 for other cylinders.

The valve push rod 13 is composed of a connecting rod portion 26 fixed to the valve stem 32 of the exhaust valve 30, and a tappet portion 27 in contact with the cam surface of the engine brake operating cam 12. The top surface of the portion 27 is processed into a cam sliding surface.

In the valve push rod 13, an adjusting screw 28 is used to adjust the position where the tappet portion 27 contacts the cam 12.
is used.

The adjuster screw 28 is formed in a sleeve shape, and the exhaust crosshead 3
4 and is adjusted with a nut 29 with respect to its exhaust crosshead 34.

The valve push rod 13 so configured also has an exhaust valve 30.
Of course, it is also possible to replace the valve stem 32 with an extension of the valve stem 32.

Next, to describe the operation of the engine brake operating device 10 described above, if the truck is going down a long slope, the exhaust brake button (not shown) on the driver's seat is pulled and the accelerator is pressed.
Release the pedal (not shown).

When the exhaust brake button is switched on, current flows through the electromagnetic coil, driving the clutch release yoke in the direction of arrow A in FIG. Accordingly, the driven side clutch
Disk 23 resists the release spring,
It is slid onto the splined portion of the engine brake camshaft 11, connected to the crankshaft side, and meshed with the drive side clutch disk 22 of the timing gear shaft 15, which is constantly rotated.

As such, its driven clutch disk 2
3 is engaged with the drive side clutch disc 22, its engine brake cam shaft 11 is engaged with its timing gear shaft 14.
The engine, brake,
The engine brake operating cam 12 located on the camshaft 11 is also rotated.

As such, its engine brake cam
The shaft 11 is rotated, and its engine
When the brake actuation cam 12 is rotated, it pushes down on its valve push rod 13 against the valve spring, causing the intake rocker arm and the exhaust rocker arm to move downward.
In connection with the valve opening and closing operations of the rocker arm 37, the exhaust valve 30 is additionally opened and closed with a slight valve lift from the end of the compression stroke to the middle of the expansion stroke in the cylinder, and the compressed air is from inside the cylinder to the atmosphere.

Therefore, sufficient exhaust braking force is obtained for the engine, and the lack of exhaust braking force of the engine is resolved, and as a result,
The truck is effectively braked on its downhill slope.

Conveniences and Benefits of the Invention As understood from the above, the engine brake operation device of this invention is related to the valve opening/closing operation of the exhaust rocker arm that is swingably supported on the rocker arm shaft in the engine. The engine is located on the cylinder head independently of its rocker arm shaft to open and close the exhaust valve.
between a brake cam shaft and an engine brake operating cam fixedly arranged on the exhaust brake cam shaft in correspondence with its exhaust valve; a valve push rod located on the valve stem of the exhaust valve and associated with the engine brake camshaft, located on the cylinder head and driven by the engine. A timing gear shaft, a driving side is fixedly supported on the timing gear shaft, and a driven side is supported on the engine brake cam shaft so as to be able to reciprocate and not rotate. The engine, brake, cam,
a timing clutch that engages and engages the shaft and is driven by a drive means independent of the exhaust rocker arm and a push rod for the exhaust rocker arm, the engine brake operating cam being driven by a drive means independent of the exhaust rocker arm and a push rod for the exhaust rocker arm; Since the exhaust valve is additionally slightly opened and closed in conjunction with the opening and closing operation of the valve of the exhaust rocker arm, the engine brake operation device of this invention has the advantage that the engine is an air compressor that absorbs power. When used as an exhaust braking means for an engine, setting the exhaust valve timing, i.e. additional exhaust valve timing, is accurate and easy, allowing the exhaust valve to operate under optimum conditions for the engine. From the end of the compression stroke to the middle of the expansion stroke, the exhaust is additionally opened and closed slightly.
Valve brake motion is obtained, and the air compressed during the engine's compression stroke is exhausted to the atmosphere from the end of the engine's compression stroke to the middle of the engine's expansion stroke, and the exhaust braking by the engine is accordingly performed. Sufficient power is obtained, the lack of exhaust braking in the engine is resolved, and the vehicle is effectively braked by the exhaust brake when going down a long hill, improving driving stability. , the equipment is mechanically integrated as a whole, and the engine, brake, cam, and shaft are
By becoming independent from the arm shaft,
The entire device is simplified and miniaturized, can be easily placed on its cylinder head, i.e. is very easy to lay out, and has no additional mechanism for slightly opening and closing the exhaust valve. The hydraulic operating cylinder and its fluid circuit are omitted, avoiding operational delays due to the fluid circuit, making it widely applicable to various engines, increasing versatility, especially in space-constrained engine compartments. This makes it very useful and practical for vehicle engines. Relationship between the invention and specific examples As mentioned above, from the specific examples of this invention explained with reference to the drawings, for those who have ordinary knowledge in the technical field to which this invention pertains,
Various design modifications and changes can be easily made, and furthermore, the content of this invention is essential to the establishment of the invention that accomplishes the task of the invention,
It originates from the technical essence of the invention, which is the nature of the invention, and can be easily replaced by a mode that is objectively recognized as incorporating it.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a specific example of the engine brake operating device of the present invention when applied to a diesel engine of a truck and the engine is used as an exhaust brake means, and FIG. , is a perspective view of an engine brake cam shaft and an engine brake operating cam of the engine brake operating device shown in FIG. 1; 11... Engine brake cam shaft, 12, 19, 20... Engine brake operation cam, 13... Valve push rod, 1
4...Timing gear shaft, 15...Timing gear, 16...Timing clutch, 17...Timing belt, 31, 31...
...Exhaust valve.

Claims (1)

[Claims for Utility Model Registration] In an engine, an exhaust rocker arm shaft that is swingably supported by a rocker arm shaft.
an engine brake cam shaft disposed on the cylinder head independent of the rocker arm shaft to open and close the exhaust valve in connection with the valve opening and closing action of the arm; and the exhaust valve. an engine brake operating cam fixedly disposed on the exhaust brake cam shaft, and a valve cam of the exhaust valve located between the exhaust valve and the engine brake operating cam, corresponding to the a valve push rod attached to the stem; a timing gear shaft disposed on the cylinder head and driven by the engine in conjunction with the engine brake cam shaft;・Fixedly supported on the gear shaft, and supported on the engine brake cam shaft on the driven side so as to be able to slide back and forth, so that the engine brake cam shaft is connected to the timing gear shaft. An engine brake operating system including an intermittent timing clutch.