GB2207731A - Hydraulically operated injection timing gear for a fuel injection pump - Google Patents
Hydraulically operated injection timing gear for a fuel injection pump Download PDFInfo
- Publication number
- GB2207731A GB2207731A GB08817278A GB8817278A GB2207731A GB 2207731 A GB2207731 A GB 2207731A GB 08817278 A GB08817278 A GB 08817278A GB 8817278 A GB8817278 A GB 8817278A GB 2207731 A GB2207731 A GB 2207731A
- Authority
- GB
- United Kingdom
- Prior art keywords
- timing gear
- injection timing
- piston
- injection
- component
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000002347 injection Methods 0.000 title claims abstract description 53
- 239000007924 injection Substances 0.000 title claims abstract description 53
- 239000000446 fuel Substances 0.000 title claims abstract description 7
- 238000002485 combustion reaction Methods 0.000 claims abstract description 12
- 239000012530 fluid Substances 0.000 claims description 2
- 239000003921 oil Substances 0.000 description 4
- 238000006073 displacement reaction Methods 0.000 description 2
- 230000002093 peripheral effect Effects 0.000 description 2
- 238000010276 construction Methods 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000010687 lubricating oil Substances 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 230000001960 triggered effect Effects 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- F16D3/00—Yielding couplings, i.e. with means permitting movement between the connected parts during the drive
- F16D3/02—Yielding couplings, i.e. with means permitting movement between the connected parts during the drive adapted to specific functions
- F16D3/10—Couplings with means for varying the angular relationship of two coaxial shafts during motion
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D1/00—Controlling fuel-injection pumps, e.g. of high pressure injection type
- F02D1/16—Adjustment of injection timing
- F02D1/18—Adjustment of injection timing with non-mechanical means for transmitting control impulse; with amplification of control impulse
- F02D1/183—Adjustment of injection timing with non-mechanical means for transmitting control impulse; with amplification of control impulse hydraulic
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Fuel-Injection Apparatus (AREA)
- High-Pressure Fuel Injection Pump Control (AREA)
Abstract
A hydraulically operated injection timing gear for a fuel injection pump, comprises a primary component 3, Fig 2, driven by the internal combustion engine and a secondary component 4 rigidly connected to the camshaft 2 of the injection pump, and pistons 6 which, when subjected to oil pressure, counteract a resetting force 15. The pistons have a wedge-shaped face 9 and which, assisted by centrifugal force, and guided in the secondary component 4, have a radial component of motion in such a manner that wedge-shaped faces supported on cooperating parts 10 on the primary side run parallel to the axis of the camshaft 2. <IMAGE>
Description
Hydraulically oPerated injection timing gear for a fuel
injection pump
The invention relates to a hydraulically operated injection timing gear for a fuel injection pump, which injection timing gear controls the beginning of injection depending on various operating parameters of an aircompressing injection-type internal combustion engine, comprising a primary component driven by the internal combustion engine and a secondary component rigidly connected to the camshaft of the injection pump, and comprising at least one piston which is displaceable in a cylindrical recess in opposition to a resetting force and has a wedge-shaped face in constant contact with a bearing surface of a cooperating part of the injection timing gear.
DE 33 45 343 C 2 discloses an injection timing gear of this type with the aid of which the injection timing can be varied depending on speed and load and also other conditions. The movement of the secondary component relative to the primary component is effected by a piston, which is guided with axial displacement in the primary component, and a cooperating part which comprises a radially extending bolt rigidly mounted in the secondary component. The piston slides with its wedge-shaped face along this bolt when pressure is applied or relieved, the effective direction of the wedge-shaped face running in the peripheral direction of the primary component.
The. problem underlying the invention is, in view of the design according to DE 33 45 343 C 2, to design an injection timing gear in such a manner that, in addition to a simplified construction, adjustment of the injection timing using low hydraulic pressures is also possible.
According to the present invention there is provided a hydraulically operated injection timing gear for a fuel injection pump in an air-compressing injection-type internal combustion engine, comprising a primary component driven by the internal combustion engine and a secondary component rigidly connected to the camshaft of an injection pump and comprising at least one piston which, when subjected to fluid pressure, counteracts a resetting force and which is guided in a cylindrical recess having a radial component of motion and assisted by centrifugal forces, and combines with a cooperating part of the injection timing gear to adjust the beginning of injection, wherein the piston has a single wedge-shaped face running parallel to the axis of the camshaft and supported against a bearing surface on the cooperating part on the primary side.
Because of the effective direction of the piston it is possible to actuate the injection timing gear using a low pressure, for which the oil pressure of the internal combustion engine is sufficient, because the piston with the radial component of motion is assisted by centrifugal forces which increase as the speed rises. A further advantage is obtained because an emergency drive operation controlled by the effect of centrifugal forces is possible in the event of failure of the pressure triggering means.
A hydraulically operated injection timing gear having a piston executing radial movements is known from
German Offenlegungsschrift 26 49 986, but this piston is not assisted by centrifugal forces during operation; on the contrary, it counteracts occurring centrifugal forces together with a spool valve which controls the pressure oil. Joint displacement occurs radially inwards in the direction of the axis of the drive shaft when the speed is increased.
The bearing surface may be on a bearing mounted on a bolt rigidly connected to the primary component.
Preferably, the wedge-shaped face on the piston is curved, and the end of the piston which is subjected to pressure may comprise a hollow bore.
In a preferred embodiment, the piston is in the form of a radial piston having a radial direction of movement, and further, the piston may have, in addition to a radial component of motion, a circumferential component.
The invention will now described in more detail below by way of example with reference to the drawing in which:
Fig. 1 shows, in section along the line I-I in Fig.
2, an illustrated injection timing gear, with two pistons which have flatly designed, wedge-shaped faces,
Fig. 2 shows the injection timing gear with a differently shaped face on the pistons,
Fig. 3 shows the injection timing gear with a differently shaped face on the pistons,
Fig. 4 shows the injection timing gear with hollowed pistons,
Fig. 5 shows the injection timing gear with pistons offset relative to one another, and
Fig. 6 shows the injection timing gear having three pistons.
A hydraulically operated injection timing gear 1 for controlling the injection timing in air-compressing injection-type internal combustion engines, is mounted on the camshaft 2 of a conventional injection pump (not shown), and consists of a primary component 3 on the drive side and secondary component 4 on the injection pump side which is rigidly connected to the camshaft 2.The component 4, has for receiving pistons 6 assisted by centrifugal forces, two diametrically opposite cylindrical recesses 7, the axes of which run perpendScular to the camshaft axis 8 (Figs. 1,3,4) or tangentially approximately perpendicular to the camshaft axis 8 (Fig 5), the movement of the pistons 6 occurring in one case only in-the radial direction, whereas in the other case (Fig. 5) the movement of the pistons 6 is divided into a radial component of motion and a peripheral component.
The pistons 6 according to Fig. 5 are thus in an offset arrangement relative to the one another. Because of this special arrangement the influence of centrifugal forces can be reduced accordingly.
Each piston 6 is provided with a wedge-shaped face 9 which has a flat design and lies parallel to the axis 8 of the camshaft 2, that is inclined to a longitudinal central plane of the injection timing gear 1 running through the piston 6.
In place of the flatly designed face 9 on the piston according to Fig. 1, a wedge-shaped face having a curve path according to Fig. 3 which is adapted to the requirements of the internal combustion engine can be provided for a specific adjusting characteristic.
Fig. 4 shows an embodiment in which the pistons 6 are hollowed for the purposes of improving the basic adjustment of the injection timing gear.
The pistons 6 are associated with cooperating parts 10 which are in the form of roller bearings, plain bearings or needle bearings and are mounted on a bolt 11 which run parallel to the camshaft axis 8 and are in turn rigidly screwed into the rotatably mounted drive wheel 12 of the primary component 3 (Fig. 2). If necessary, fastening can also be effected by pressing the bolts into the drive wheel.
The primary component 3 and secondary component 4 are provided with oppositely lying recesses 13, 14 in which are guided supported resetting springs 15 which, when subjected to pressure; counteract the movement of the pistons 6 and which, when pressure is relieved, guide the pistons 6 back again into their original position.
The control and admission of lubricating oil takes place via feed holes 16 extending from the injection pump, an annular gap 17 and a throttling port 18 in the camshaft 2, and also yia a radial bore 19 in the secondary component 4 and finally into a pressure chamber 20 defined by the cylindrical recess 7 and the radial piston 6.
The inflow or outflow of pressure oil to vary the injection timing is regulated by way of a servo valve (not shown) which is triggered by a control electronic system and forms part of the oil circuit of the internal combustion engine.
The provided throttling port 18 serves to damp vibrations occurring in the event of adjustments of the injection timing gear at the beginning of injection.
Instead of two pistons 6 three or more pistons can also be guided if necessary in the injection timing gear 1, these pistons being arranged in rotational symmetry.
Claims (7)
1. Hydraulically operated injection timing gear for a fuel injection pump in an air-compressing injection-type internal combustion engine, comprising a primary component driven by the internal combustion engine and a secondary component rigidly connected to the camshaft of an injection pump and comprising at least one piston which, when subjected to fluid pressure, counteracts a resetting force and which is guided in a cylindrical recess having a radial component of motion and assisted by centrifugal forces, and combines with a cooperating part of the injection timing gear to adjust the beginning of injection, wherein the piston has a single wedge-shaped face running parallel to the axis of the camshaft and supported against a bearing surface on the cooperating part on the primary side.
2. Injection timing gear according to claim 1, wherein the bearing surface is on a bearing mounted on a bolt rigidly connected to the primary component.
3. Injection timing gear according to claim 1 or 2, wherein the wedge-shaped face on the piston is curved.
4. Injection timing gear according to any one of the preceding claims, wherein the end of the piston which is subjected to pressure comprises a hollow bore.
5. Injection timing gear according to any one of the preceding claims, wherein the piston is in the form of a radial piston having a radial direction of movement.
6. Injection timing gear according to any one of claims 1 to 5, wherein the piston has, in addition to a radial component of motion, a circumferential component.
7. Hydraulically operated injection timing gear for a fuel injection pump in an air-compressing injection-type internal combustion engine substantially as described herein with reference to, and as illustrated in, the accompanying drawings.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE3724211 | 1987-07-22 |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB8817278D0 GB8817278D0 (en) | 1988-08-24 |
| GB2207731A true GB2207731A (en) | 1989-02-08 |
| GB2207731B GB2207731B (en) | 1991-03-06 |
Family
ID=6332088
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8817278A Expired - Fee Related GB2207731B (en) | 1987-07-22 | 1988-07-20 | Hydraulically operated injection timing gear for a fuel injection pump |
Country Status (3)
| Country | Link |
|---|---|
| FR (1) | FR2618487A1 (en) |
| GB (1) | GB2207731B (en) |
| IT (1) | IT1218013B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2660372A1 (en) * | 1990-04-02 | 1991-10-04 | Renault Vehicules Ind | AUTOMATIC HYDRAULIC INJECTION ADVANCE DEVICE. |
| DE4323671A1 (en) * | 1993-07-15 | 1995-01-19 | Schaeffler Waelzlager Kg | Continuously variable camshaft adjustment |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2066986B (en) * | 1980-01-03 | 1983-06-02 | Renault Vehicules Ind | Hydraulic automatic device for the injection advance of a diesel engines |
| DE3345343C2 (en) * | 1983-12-15 | 1986-10-23 | Daimler-Benz Ag, 7000 Stuttgart | Hydraulically operated injection adjuster for the fuel injection pump of a self-igniting internal combustion engine |
| DE3701852C1 (en) * | 1987-01-23 | 1987-11-12 | Daimler Benz Ag | Damping device for a centrifugal injection timing adjuster |
-
1988
- 1988-05-27 IT IT20780/88A patent/IT1218013B/en active
- 1988-07-20 FR FR8809813A patent/FR2618487A1/en active Pending
- 1988-07-20 GB GB8817278A patent/GB2207731B/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2660372A1 (en) * | 1990-04-02 | 1991-10-04 | Renault Vehicules Ind | AUTOMATIC HYDRAULIC INJECTION ADVANCE DEVICE. |
| EP0452187A1 (en) * | 1990-04-02 | 1991-10-16 | Renault Vehicules Industriels | Hydraulic automatic injection advance device |
| DE4323671A1 (en) * | 1993-07-15 | 1995-01-19 | Schaeffler Waelzlager Kg | Continuously variable camshaft adjustment |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2207731B (en) | 1991-03-06 |
| FR2618487A1 (en) | 1989-01-27 |
| IT1218013B (en) | 1990-03-30 |
| GB8817278D0 (en) | 1988-08-24 |
| IT8820780A0 (en) | 1988-05-27 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |
Effective date: 19920720 |